The Inside Track on Firefox Development.

February 14, 2006

About the Firefox "memory leak"

A lot of people complain about the Firefox "memory leak(s)". All versions of Firefox no doubt leak memory - it is a common problem with software this complicated. We look to fix the issues where we can. David Baron and others have done a huge amount of excellent work in this area.

What I think many people are talking about however with Firefox 1.5 is not really a memory leak at all. It is in fact a feature.

To improve performance when navigating (studies show that 39% of all page navigations are renavigations to pages visited < 10 pages ago, usually using the back button), Firefox 1.5 implements a Back-Forward cache that retains the rendered document for the last few session history entries. This can be a lot of data. It's a trade-off. What you get out of it is faster performance as you navigate the web.

For those who remain concerned, here's how the feature works. Firefox has a preference browser.sessionhistory.max_total_viewers which by default is set to -1. When set to this value, Firefox calculates the amount of memory in the system, according to this breakdown:

RAM	Number of Cached Pages
32MB	0
64MB	1
128MB	2
256MB	3
512MB	5
1GB	8
2GB	8
4GB	8

(reference: nsSHistory.cpp)

No more than 8 pages are ever cached in this fashion, by default. If you set this preference to another value, e.g. 25, 25 pages will be cached. You can set it to 0 to disable the feature, but your page load performance will suffer.

Edit: In the comments, Boris and David pointed out that I misread the code, and that this is a global preference so that there are no more than 8 cached pages for the entire session, not per tab. My initial posting had claimed that it was per-tab. Oops!

Posted by ben at February 14, 2006 9:34 AM

Comments

How do other browsers (Opera for instance) use fastback-like technology without ramping up their browser's memory consumption? Is it a design flaw?

Posted by: Simplex at February 14, 2006 10:38 AM

Well I'm quite tired of people complaining about this subject. Thanks for the explanation.

Posted by: Ken Saunders at February 14, 2006 10:59 AM

I think the all-tab memory cache is the cause of a lot of "memory leak" moaning and groaning too, you should probably talk about that also (e.g. if you start a new Firefox, open a bunch of tabs, then close them all, the memory usage doesn't go down much because you've just populated the memory cache).

Posted by: Justin Kerk at February 14, 2006 11:08 AM

Maybe 8 is not the best upper limit?

Do users *really* need to go back 8 times? People usually does back a couple of times but 8....

Posted by: Diego at February 14, 2006 11:16 AM

Hmm, because I have tabs I don't use the back-button very often any more. If I expect to return to my current page, I open the new page in a tab instead. Actually tabs has totally changed the way I surf the net, and I'm very happy about that change.
I've got 2GB memory, so guess I should definitely change this setting. It's not completely unuseal that I got 10+ tabs open at once!

Posted by: Stig at February 14, 2006 11:21 AM

While there are still some problems with Firefox itself and memory leaks, from my experience most memory leaks comes from certain extensions. I believe Jesse Ruderman has talked about this also and pointed out some popular extensions that have caused problems. I believe it is becoming absolutely necessary to set up some detailed review process before extensions are added to the Mozilla site. Fair or not any problems caused by an extension most people will blame on the Firefox product itself. I believe now the process is just focused on making sure extensions work, and install/uninstall correctly. Will we ever see any sort of more detailed review process before extensions can be added to the add-on site?

Posted by: Leslie Franke at February 14, 2006 11:23 AM

...And I have never gone 8 times back, not in the old days without tabs either. And even if I seldom wanted to go 8 steps back, it would be such a speciel situation that I wouldn't care much about the speed.
But I might ofcourse not be an average user:-)

Posted by: Stig at February 14, 2006 11:24 AM

Perhaps it would be helpful to post an addendum describing the average memory usage of one cached page at a few common sites.

Posted by: RA at February 14, 2006 11:27 AM

Users with a lot of tabs, really need 5/8 "back-forward cache" per tabs ?

Seems to be better to reduce cache max when tabs number increase like this:

RAM: 1Go
1 tab => 8
10 tabs => 5
20 tabs => 3

Posted by: boris at February 14, 2006 11:29 AM

I think Simplex has a point. Opera uses tabs, just like Firefox, but they don't seem have any problems with memory.

What are they doing different? It would be interesting to know, because memory leak is a serious problem in Firefox, for those of us who don't have RAM to spare.

Regards,

Omar.-

Posted by: Omar Upegui R. at February 14, 2006 11:32 AM

I think it'd be way less confusing for people if there was a setting like "Amount of memory dedicated to Fastback" which would then be shared by fastback for all open tabs.

Posted by: lukem at February 14, 2006 11:44 AM

Ben my man, that worked. FF went from hogging 250MB of my ram to a swift 54MB with the same tabs and page clicks. Where were you 5 months ago ;)

Posted by: Jim Plush at February 14, 2006 11:53 AM

Guys, remember: unused RAM is wasted RAM.

Posted by: David Naylor at February 14, 2006 12:03 PM

Maybe the devs there at Opera know something, but even this explains a lot. thanks.

Posted by: PAStheLoD at February 14, 2006 12:04 PM

Concur with Boris. Smarter caching is in order here - simple solution that would do the world a great deal of help.

Make the #history per inactive tab something like:

Max caches total = 8 + (tabs*log2(tabs))/(some-fungible-performance-constant)

Distribute caches by following:

Current tab = 8
Other tabs = remaining/(current tab count - 1)

That would be a great starting point. Maybe I can help writing it myself with you. Never done OSS in the past... perhaps there is no time like the present.

Posted by: SourAaron at February 14, 2006 12:09 PM

Why does it need to remember these _per tab_? Isn't it a whole lot more efficient to keep an 8 page cache in general, over all tabs? At least then tabs can reuse each others cache (or can they already now, in which case keeping a cache per tab is even more strange)

Or in fact, when you keep it general instead of per tab, you can up this limit easily to 12 or 16.

Posted by: Paul at February 14, 2006 12:12 PM

whew, thank you for explaining this to all the idiots who've been calling this a memory leak issue. ive been trying to explain what you just wrote to everyone who's said this in the past (a LOT of people).

but i also agree with some of the comments here, 8 fastbacks isnt really necessary..

"Users with a lot of tabs, really need 5/8 "back-forward cache" per tabs ?

Seems to be better to reduce cache max when tabs number increase like this:

RAM: 1Go
1 tab => 8
10 tabs => 5
20 tabs => 3"

i thought this was a great solution. maybe next version firefox could use this system?..

also some people were mentioning opera as using the same feature without using memory. first of all, opera and firefox are both made by the same company.

second, its impossible for any browser that has the same feature to do so without using alot of memory. pages in memory are the same size no matter what browser. i suppose they could be compressed before they go into memory, but that would make things slow. expecially for older computers.

Posted by: daniel at February 14, 2006 12:16 PM

"Guys, remember: unused RAM is wasted RAM."

Yes but when Firefox eats up ALL of your ram and then the swap file as well then you have problem.

Users don't want to hear its because of a "poorly coded webpage" or "it's your flash plugin". They just want to use a brower that doesn't leak memory like there is no tommorrow. I think that is a resonabel request especially since that is what they are used to when they use other web browsers.

Posted by: user at February 14, 2006 12:16 PM

For me the issue is returning memory to the system. I once had Firefox using more then 800megs of memory with only one window containing one tab open. Over the past couple of days I had used dozens of windows with many dozens of tabs. Over this time I had had at least one Firefox window open at all times. It seems like all the caching from closed tabs was still using memory (if this was the cause of the stupid amount of memory usage). In order to return all the memory to the system I have to close all Firefox windows.

Posted by: Adam at February 14, 2006 12:17 PM

How would one go about changing this setting?

Posted by: maxpower at February 14, 2006 12:20 PM

So this explains why leaving Firefox running, with one tab open and no activity, all night long results in it eating up an extra 60MB of memory?

Interesting. This feature is sounding very Microsoftish.

Posted by: Strictnein at February 14, 2006 12:21 PM

Thanks for the explaination.

I have FireFox on a few systems with different amounts of memort and I can honestly say that the memory leak issue hasn't been a big deal at all.

Thanks for a greater browser!

Posted by: Matt at February 14, 2006 12:23 PM

>They just want to use a brower that doesn't leak
> memory like there is no tommorrow.

er, this is not a memory leak. the memory is freed if you close the tab.

Posted by: christian biesinger at February 14, 2006 12:27 PM

I'm so glad I found this today. I use Firefox 1.5 on a laptop with 2GB of RAM. Last night, i noticed that Firefox alone was eating up 600MB of RAM. I thought to myself, "why is a web browser eating up so much memory?". Now that I read this explanation, it all makes sense. I had several tabs (11, 12?) open, all with large images (artwork from allposters.com). I'd been browsing that site for a few hours, and given all of the graphical elements, it certainly makes sense. But oddly enough, the "snappiness" that you would expect to see from having everything cached in RAM wasn't really there. Firefox actually slowed down other apps running concurrently, due to the bloat. I went ahead and disabled this feature, and will try to navigate to image heavy sites to see if there is a difference in memory consumption.

Posted by: ThoughtCancer at February 14, 2006 12:28 PM

BS.

So when I close all tabs and close firefox, and it's STILL running, is that a feature?

It happens on both of my machines sometimes.

1.5 is a big disappointment. I have no problems with Opera.

Posted by: Matt at February 14, 2006 12:31 PM

Maybe you could get some inspiration from KHTML - it seems to manage this with only about 20KB per page, whereas Firefox goes up about 150KB for each page.

Posted by: ant at February 14, 2006 12:32 PM

So how do I access "browser.sessionhistory.max_total_viewers" to edit the value??

Posted by: Dino at February 14, 2006 12:33 PM

I must be special, 'cause I've never had Firefox use more than 100 MB RAM. Never. Right now, it has been running for several hours (and not just sleeping), and it's at around 62 MB. Not that bad if you ask me.

Posted by: Veracon at February 14, 2006 12:34 PM

Doesn't firefox fall back to the disk cache? And won't most recent pages be in the disk's in memory cache? I'd like to understand what the performance gain is before sacrificing memory, especially if the data is already cached at by another subsystem.

Posted by: paul at February 14, 2006 12:34 PM

"first of all, opera and firefox are both made by the same company."

You are very confused.

Posted by: Ben at February 14, 2006 12:35 PM

So, with the feature set to -1, lets say I 64MB of RAM free, from the chart I would get one page cached. If I opened up another program that brought my free RAM down to 24MB, would FF immediately cough up the cached page freeing up more RAM? If yes, that's pretty slick. No need to reduce the top end 8-page cache, in fact might as well crank it up to 9 or 10.

Posted by: mawrya at February 14, 2006 12:38 PM

How about having Firefox automaticallly release page caches when memory is running low so it will never uses the swap file?

Posted by: Eka at February 14, 2006 12:38 PM

How feasible would it be to flush the bfcache to disk on unfocused tabs?

This way switching tabs would load the current tab's bfcache into RAM and unload the previously focused tab's bfcache from RAM to disk.

This might not be feasible due to performance concerns on some machines, but a background load/flush seems at least theoretically possible. Thoughts?

Posted by: Brad Fults at February 14, 2006 12:39 PM

"also some people were mentioning opera as using the same feature without using memory. first of all, opera and firefox are both made by the same company."

ROFLMAO ... thanks, I needed that.

Posted by: Jorgie at February 14, 2006 12:40 PM

"I once had Firefox using more then 800megs of memory with only one window containing one tab open."

I'll see your 800 and raise you to, wait for it, 954MB!

Posted by: Maz at February 14, 2006 12:41 PM

Even with the newly improved 'Fastback' feature, it seems that Firefox is still slow to go back, unlike Opera which goes back without slightest delay. Anyone know why this is?

Posted by: Zeke at February 14, 2006 12:42 PM

when i first noticed the memory leak (call it what you will) the first thing i tried was closing all tabs; this never worked to release the memory. it has gotten to the point where i will no longer use firefox for work-related activity because a crashing browser is not really an option. i just changed the setting, hopefully it will resolve the issue/feature.

Posted by: matt at February 14, 2006 12:45 PM

So how do I access "browser.sessionhistory.max_total_viewers" to edit the value??

Open up a blank window, then go to the 'address' about:config. Then scroll down until you find it.

Posted by: phil at February 14, 2006 12:45 PM

When I use tabs, it's to avoid using the Back button and surf faster.

However, I know of at least 5 newbies users that are confused about tabs and avoid them. (I tried to explain but it still blows them away.)

Therefore this caching parameter should be dynamic so that it caches 8 pages when there is only one tab (or no tab) and 2-3 pages per tab when you have many tabs. More than that it's no gonna get used.

Posted by: Denis at February 14, 2006 12:45 PM

so why does the memory usage grow in this scenario:
1. got to one page
2. click a link to another one
3. click tha back button
4. click the forward button
5. repeat step 3

also i just observed that the usage grew when i closed a tab.

i now have only this page opened (in a new tab, no back or forward is possible, except using the go menu) and the memory usage did not go down a byte compared to what the value it reached during the browsing in other tabs before.

if i have no way to access that cached data (using back and forward buttons) why is it still kept?

Posted by: def at February 14, 2006 12:46 PM

To the person who said:

"whew, thank you for explaining this to all the idiots who've been calling this a memory leak issue."

Step down your elitist high horse. Firefox is a browser meant for all sorts of users, many of whom would require quite a bit of explanation about what it is causing this large amount of memory consumption. It doesn't make them idiots. When a user notices more than double the size RAM taken up when using firefox than opera when doing the same sort of surfing w/o any plugins, many would naturally assume it was a memory leak issue causing the problem.

Also, like someone earlier said, I don't use back very often, if at all, because it is so much easier to just open a page in a new tab when I think I am going to refer to the older page.

Thanks to Ben for the informative data on this issue.

Posted by: Jesus at February 14, 2006 12:48 PM

Makes sense, but it seems like if I have 30 tabs open browsing for a while, then close 25 of the tabs, I don't get much memory back.

Posted by: Christopher at February 14, 2006 12:52 PM

To change stuff in firefox type this in the url space and enter.

Remember your computer will blow up if you do this. Do it at your own risks.

about:config

You have been warn! Don't you go complaining after that :)

Posted by: Alexandre at February 14, 2006 12:52 PM

dino,

to change this value, type

about:config

in your address bar.

Posted by: j.goforth at February 14, 2006 12:55 PM

Wow, that really helped. It would be great if we could control this per tab - or, i guess for saving settings, per url. I don't see a need to have deep history on, say, a calendar, rss reader or email tab. But I'd want a high setting for a search tab.

Thanks for the info, and for helping cut down the memory usage from 850mb to 220mb.

Posted by: Mark at February 14, 2006 1:01 PM

dang, you beat me to it.

Anyway, I agree with 8 pages per tab being a little silly. I personaly rarely follow more than a link or two in a single window if I have any intention of going backwards. Keeping 8 pages is rather excessive for people who fall into similar use patterns. However since there are different use patterns, I would agree with the idea of limiting the number based on the tab count. I would however add that I could see this being added to the cache page of the preferences menu. Something where I could say "Use no more than X MB of RAM" and "Clear Flashback cache"

Posted by: j.goforth at February 14, 2006 1:02 PM

Good to know this, I had thought it was a leak myself. I use a lot of tabs but it turns out the biggest culprit is my always-on Bloglines tab. Closing it freed 160 megs of VM in one instance. A regressive algorithm for the number of cached pages based on the number of open tabs could be a good thing.

Posted by: Bjorn at February 14, 2006 1:09 PM

"unused RAM is wasted RAM" and "it's not a bug, it's a feature".

Conveniently ignoring what happens in the real world - Firefox simply consumes outrageous amounts of memory, it's done it since the beginning, and there has been no clear logic behind it. Fastback cache is a nifty excuse for the newer version(s), but doesn't explain at all why the previous versions hogged RAM until FF simply died or was killed.

Of course, calling it a "memory leak" might not be the most accurate way to describe it... but then again, if an application doesn't free up unused, unnecessarily reserved memory at any point, what should it be called? :D

This particular fix helps the situation somewhat, and I am grateful for it. However, I use all Big 3 on a daily basis, and so far the FF chews up more memory when viewing the same amount of pages (tabs in Opera, separate windows in IE). And since the memory is never released... that means several FF restarts every day.

It's been like this since the beginning, and hasn't improved. These experiences were gathered from the early betas to the latest official release, on Windows, on several machines. So it's definitely an issue in FF.

It's by far the best browser I've seen, but as an application on Windows, it's so-so.

Posted by: Rrright at February 14, 2006 1:09 PM

I wholly reject this explaination as to the source of problems with Firefox.

1 - 1.07 had GREAT performance, did it not use the same algorithm?

2 - When I see that FireFox is taking up 450,000k of memory, I close all of my tabs except for the last one. My memory usage (in Windows Task Manager) shows no reduction in memory usage. SO, my 1 tab, with Google on it is taking up 450,000k

3 - I (attempt) to have Firefox open for many days at a time. The memory issue never grew out of control with 1.07, but I cannot have Firefox 1.5.0.1 open for more than half a day before it eats up all of my memory.

4 - Firefox is geared for the more sophisticated web user (hence all the extra buttons and features) - the only time I use my back button is on web sites that are poorly designed.

5 - I get "phantom" Firefoxes in my Task Manager. No UI for these instances of Firefox. Flamers blame Windows, yadda yadda, whatever, the fact remains that something is up with Firefox, and it's not a tab cache issue. Period.

In an odd way, I am glad for this memory issue though. It has forced me to seek out other browsing alternatives (beyond IE and Firefox), and made me get off my duff to finally look at Opera (which kicks butt BTW).

Firefox needs to seek its "roots" once again, and quit talking about V2.0 and V3.0 until V1.5 is safe and secure to operate.

Posted by: Eric at February 14, 2006 1:10 PM

Why opera may be faster on reloads.

They might cheat, and ignore cache headers so instead of a refresh from the server, they merely pull from their disk cache.

I've found 1.5.0.1 to be better behaving than the previous ones. Wonky javascript sites don't slow my browser down as much as they used to. Apparently, the JS engine in Firefox/Mozilla doesn't handle some outmoded non-std javascript functions that sites written to IE use. These can cause Firefox to slow to a crawl, and even eat ram. Why? I don't know. I do encounter this left often. And sites that adhere to more std javascript code don't cause many problems anymore.

That said, my 1.5.0.1 hasn't hogged memory or run away on me yet.

Posted by: Daniel Joyce at February 14, 2006 1:13 PM

I got sick of these memory leaks that caused to system lock ups and slow preformace. This user has switched to Opera for now.

Posted by: Jason at February 14, 2006 1:15 PM

It becomes a memory leak when you open and close many tags. Firefox does not properly free this memory. So as you open and close new tabs, the memory usage continues climbing without ever going down. This constitutes a memory leak, as memory is used, but never freed.

Posted by: Adam Zey at February 14, 2006 1:17 PM

The limit of 8 pages per tab it's quite high, more taking into account that probably most of the people that uses tabs use the back button much less than previously.

I think that this feature needs some automatic training: if the user never clicks the back button then disable it, if the user clicks it then see how many pages he goes back, maybe one, maybe 2-4, more?, I wouldn't really expect fast back behaviour going back more than 2 pages.

So the system self-trains according to how the user behaves avoiding the waste of memory for those than aren't going to use this feature and using as less memory as possible for those that use the back button.

Anyway, a global Max for the total of pages in the back history could be a good idea.

But also the extensions need lots of attention, if a user is welcome to a.m.o. suggesting that those extensions are the most used ones, but it happens that some of those extensions give trouble (like it has been happening with Adblock) they won't understand a thing.
In a similar though, the Extend Firefox Contest winners should be choosen very carefuly, as many people will install them "because they are choosen as the best ones". I have to say it: I can't believe that IE Tab is choosen as a finalist, sorry that's offtopic, but it can bring all the problems of IE to Firefox.

Posted by: Alfonso at February 14, 2006 1:17 PM

This addresses some people's memory issues regarding tabs but there still exists another problem area: opening new windows. I've tracked memory and handles for firefox.exe while opening new tabs and new windows. When tabs are closed, the consumed memory is almost all returned. However, when closing new windows, the memory and handle count remain high.

I'll be trying a more scientific experiment in the near future but in the past 15 minutes I've observed that:
- Firefox consumes 25MB with one window (about:blank)
- Opening Google homepage adds 2-3MB
- Opening Google homepage in 25 tabs adds ~25MB
- Closing those tabs returns memory to ~35MB
- Repeating those steps nets roughly the same end result

Now, if I those same steps using new windows rather than tabs, the end result is 116MB of memory used!!! Repeating the steps brings that usage up even higher!

Please explain that.

Posted by: CDub at February 14, 2006 1:20 PM

"1 - 1.07 had GREAT performance, did it not use the same algorithm?"

No, the back-forward cache it's a new feature of 1.5, so the same algorithm isn't possible.

Posted by: Alfonso at February 14, 2006 1:20 PM

Interesting to note. Thanks for the correction.

Posted by: Eric at February 14, 2006 1:22 PM

"also some people were mentioning opera as using the same feature without using memory. first of all, opera and firefox are both made by the same company."

Your a dumbass.

Posted by: Selby at February 14, 2006 1:25 PM

"You're a dumbass." Not "Your a dumbass."

Dumbass! (just kidding about the last dumbass part lol)

Posted by: Eric at February 14, 2006 1:28 PM

if closing tabs doesn't reclaim the memory, then it's not bfcache causing the problem

Posted by: christian biesinger at February 14, 2006 1:30 PM

Question -

Do the extensions have a big effect on memory, depending on the extension? I would think that, since you don't have a lot of control of extensions, and someone can have 50 extensions to their browser, this would really hit the memory as well, right?

Anyone help me out here?

Posted by: JC at February 14, 2006 1:31 PM

Ben, those numbers are NOT per tab. The bfcache is global; there are never more than 8 pages total in bfcache (and you need to have 1GB of RAM for this to happen). Most users have 3 or 5 pages in bfcache at any given time.

Posted by: Boris Zbarsky at February 14, 2006 1:33 PM

The point of bug 292965 was that the pref should be global, not per-tab. Is that not working correctly?

Posted by: David Baron at February 14, 2006 1:34 PM

Forget that, on more than one machine I have access to Firefox when launched will not appear. Then when you pull up the task manager it shows as a process consuming increasing amounts of RAM eventually crashing the machine.

After asking around this appears to be a common bug.

This happens without plugins, but with plugins installed it seems to dramatically increase. This also creates an extra load time of the program intially by a good ten seconds if Firefox appears at all.

Posted by: Pope at February 14, 2006 1:35 PM

"For me the issue is returning memory to the system. I once had Firefox using more then 800megs of memory with only one window containing one tab open. Over the past couple of days I had used dozens of windows with many dozens of tabs. Over this time I had had at least one Firefox window open at all times. It seems like all the caching from closed tabs was still using memory (if this was the cause of the stupid amount of memory usage). In order to return all the memory to the system I have to close all Firefox windows."

This is my issue. I just don't get it. I can be at 500k usage, close the whole browser and wait for it to cleanup, then relaunch all my same tabs using sessionsaver and suddenly it's down to 50k.

I don't mind it using a lot of RAM to increase page performace. I just don't understand why it seems to be so stingy about releasing the memory.

Posted by: Daniel Talsky at February 14, 2006 1:40 PM

Thanks for the explanation.

Posted by: Heartless at February 14, 2006 1:55 PM

Memory cache and bfcache are nice, but if they are swapped to disk, the benefit is drastically reduced. At least with the memory cache I would imagine that it is better to just flush the cache if it can be detected that it is about to be swapped to disk.

In general, it may make sense to prune the memory cache and bfcache after a period of inactivity. If you haven't been using a tab or the whole browser for a while or a specific file in the memory cache, you probably wont mind waiting a little longer for the page/file to load.

Well, just some random thoughts :-)

Posted by: Christian Schmidt at February 14, 2006 2:01 PM

If you're having weird problems with Firefox like frequent crashing, bad memory leaks, or it stays running when closed I suggest trying a clean profile, here are instructions on how to do that.

This backs up your old profile so you can easily switch back to how things are now if the procedure doesn't help. This is for Windows but other OS users should be able to figure out the different directory locations.

Optional - Make a list of your extensions or download the latest versions all into one folder for easy installation.

Close Firefox, make sure it's closed by checking the task list if needed.
Rename the profile directory to Firefox-old. Note that "application data" is a hidden folder.
"C:\Documents and Settings\[user name]\Application Data\Mozilla\Firefox"

Uninstall Firefox from add/remove programs. Then delete the "C:\Program Files\Mozilla Firefox" folder to make sure it's completely gone.

Install the latest version of Firefox and run it.

Import your old bookmarks from the old backed up profile.
"C:\Documents and Settings\[user name]\Application Data\Mozilla\Firefox-old\Profiles\[random string].default\bookmarks.html"

Use Firefox for a while without installing any extensions to see how well it's running and hopefully the problems will be solved.

If a clean profile doesn't help at all and you want to go back to how things were you can close Firefox, rename the new Firefox profile folder to old1 and rename Firefox-old back to Firefox.

Posted by: Malakin at February 14, 2006 2:12 PM

Okay, a simple question. I have 512M ram on my laptop and as many laptops out there it's got a slow harddrive. I could say I'm swap -wary. I dynamically open and close tabs depending on how complex what I'm doing at the moment is. I'd like to use as many tabs as I need and then to have the (once used) memory *released* on closing the unused tabs.

So how come this doesn't seem to happen? Is it not supposed to happen? Is it an extension I have installed? Do I need to remember to restart firefox every now and then, just like I did restart Windows in the 95/98 days?

Posted by: george at February 14, 2006 2:17 PM

I would like an option to only have the current page in memory, and have the past X pages stored to a prebuffered cache file. If we specify the size and you calculate how many can be stored as per how many tabs are open and the sizes of the pages needing to be stored. If i'm going back, sure I like speed, but I don't need it in RAM to see the benefits. An option for storing this in a cache swap file would be excellent. (Not little cache files everywhere, allocate space before needing it)

Posted by: Uriah at February 14, 2006 2:20 PM

How about an advanced option that has a 5 position slider that has "maximum browser speed" on one end and "minimum browser memory usage" on the other, and let users decide what's important to them.

Posted by: Chris Sherman at February 14, 2006 2:27 PM

Thats was good to know.

Posted by: computadoras at February 14, 2006 2:36 PM

Ok dumbasses, why is that Firefox starts with 20MB private memory, after a lot of browsing it goes up to 120MB private mem then with one empty window/tab and cleared caches it goes back only to 50MB? What uses that 30MB plus when there's no open page and caches are cleared?

Posted by: Sebhelyesfarku at February 14, 2006 2:38 PM

Just a bit of info: the effect of the back-forward cache is extremely obvious if you have the disk cache disabled (like Portable Firefox). If you have the time, try it. You'll see this thing actually works. On the other hand, it's not so useful when you have the disk cache enabled (like most normal people). And I agree with the usage-pattern thing. I've always used new tabs if I'm going to return to a site. Occasionally, I may go back once or twice, but that's it. IMO, their should be separate options for back and forward caches. For me, back has always been more useful than forward (If I'm going to switch back and forth, I'm opening a new tab). Again: "USAGE PATTERN"

Posted by: nolookingca at February 14, 2006 2:51 PM

Ok not sure if this was asked before but how do i CHANGE the setting. Sure its set to -1 now and that = 8 tabs or 5 tabs depending on my memory, but can someone post a chart with values for say 2 tabs or 3 tabs. What do we set the value to then? 1? 2? -3? Help?

Just a simple settings chart with what each value change the max amount of cached tabs to. Thanks!

Posted by: ZoiD at February 14, 2006 2:57 PM

it'd be nice if this were the explanation, but it's not. disabling bfcache does nothing to help. in fact, i've seen the same problems back since firefox 0.1, and before firefox was even a gleam in blake's eye. it's a memory usage problem that's been in gecko pretty much forever. i don't think it's technically a leak though, because the memory *is* being reused by firefox. it's just never being released back to the OS.

https://bugzilla.mozilla.org/show_bug.cgi?id=130157

Posted by: scratch at February 14, 2006 3:06 PM

In my experience there are only some sites where I use the back button ( Google, forums ). It would perhaps be smart to use the smart loading to handle the back button caching. Only cache one old page per tab. When the user clicks back use the pre-loading feature to go and get the next previous page. Also note when the user uses the back button on a _site_ and increase the maximum number of cached pages for that site, upto the already determined maximum. Save the per site history cache level so that it can be used in the future.

Posted by: Jon Hart at February 14, 2006 3:13 PM

First off, I am a little above average web and firefox user. I have 128MB ram and most of the time firefox consumes about 40% and 60% of it. But I dont solely blame Firefox for it, some or most of the blame should go the extensions which are developed by average programmers who dont consider memory useage. I admit that when I browse, I open up 15 to 20 tabs at a time(each link in its own tab, usually) and I rarely ever use the back botton any more. Ben, the statistics that you provided cannot be applied to firefox since those stats only apply in the age with people only used IE and only one window.
As someone of you may know there is a temporary solution to you memory woes, and that is FreeRAMXP Pro (Free as in beer) or other ram freeing softwares. Keep it on autofree and it will periodically free up wasted ram created by Firefox (no offense).

BTW, thanks Ben for this info. It helps, I think.

Posted by: TheHinduMan at February 14, 2006 3:14 PM

I'd think it is wise to build a program memory handling this way: use as much memory as needed, then if it's closed there is no need to free memory at the same time. Only when the memory taken should be freed IF it is needed by some other instance. If Firefox would be restarted it would be great to have the page info handy as soon as possible. As the pages would still be in memory the tabs would load almost instantly.
Then, if the Firefox really has a problem that it just wont release its once taken memory Then it is a real problem. Has anyone tried to get Firefox use very much memory, then shutting it down, and maybe starting some other memory hungry app to see if Firefox would give memory back?
Just my cents..

Posted by: kuvittelija at February 14, 2006 3:31 PM

Opera's previous page load time beats FF 1.5 anyday. And their Ctrl-Tab page-tab cycling is better, but that's another issue.

Posted by: cj at February 14, 2006 3:32 PM

I wish there was a way to cause firefox to ignore cache headers and simply pull a disk cache up when the back button is used.

This is generally what I want when I click 'back'. I think that most users don't click back to get to a particular URL, they do it to retrieve the content that they had originally seen.

It's too bad that Firefox seems to pull a fresh copy off the web server every time the back button is used.

Posted by: Francis Esmonde-White at February 14, 2006 3:33 PM

I only experience FF hanging more often was when I upgraded to 1.5.

Is it lso possible that with this feature along with the Session Saver extension, we get more leaked RAM?

Posted by: abe olandres at February 14, 2006 3:55 PM

I'd like to add my support to the view that tabbed browsing changes that nature of the page revisits. The statistic quoted in the original post is probbly not accurate for multitab browsing. My suggestion is that the alogorithm take into account the number of tabs open. Or better yet, the amount of activity in each tab. Typically, I have one main browsing tab with 10-15 single page tabs were I read the article and close the tab. While 8 pages might be useful for the single main browsing tab, it's total overkill for the article tabs where I only ever navigate the single article.

While some heuristic would be complicated, I submit simply limiting the cached pages for all tabs to 8 + 1/tab. So each tab would retain at least 1 cached back/forward and the other 8 would be shared slots used on an LIFO basis.

Posted by: Steve Anderson at February 14, 2006 3:58 PM

Sometimes, I find that Firefox randomly sucks up 1GB ram and 1.5GB Pagefile for no reason, when I just leave it open on one page, even when i close that tab and open up a new one.

Using Opera now, and not having any problems.

Posted by: anonymous at February 14, 2006 3:59 PM

One trick we've used in the past with our desktop and server applications to reduce memory consumtion is to store a serialized version of the memory to disk.

Before you say "Hey it already does that" .. i'm not talking about cache files. Firefox "cache" stores a copy of html and graphics, when you navigate back it needs to re-render the page which is where the overhead is incurred -- what i'm referring to is storing the actual serialized data structures in memory directly to disk.

Serializing memory to disk so it can be reloaded quickly is not only handy and only negligbly slower -- it also significantly decreases memory fragmentation (which oddly enough in many applications actually gives you additional performance by inadvertantely better utilizing your on-chip l1/l2 cache).

Posted by: Brian Horakh at February 14, 2006 4:57 PM

I'm not quite sure that this is a problem with the bfcache. Even before bfcache was enabled (and even before 1.0.x), I've had the problem where I would have the browser running for a few days without ever closing it entirely, thanks to tabs. My browsing habits are such that I usually have 20 or more tabs open at one time, and I am usually opening new tabs at around the rate that I'm closing them, which is why the browser never exits.

What I had noticed is that after a few days, even when I close every single tab, the memory usage would be high, and that memory would be released only if I exit. If I exit and then reload all 20 of my tabs (thank goodness for opening bookmark folders into tabs), the memory that I use would still be significantly less than before I closed all those tabs and exited.

To me, this sounds like the canonical memory leak. Admittedly, I might not comparing apples to apples here; it may be the case that these old memory leaks from the days of Firebird have indeed been fixed and have now replaced by bfcache and sessionsaver's leakage (and with a comfy 1.5 GB of RAM, I don't care enough to test it out ;)), but I thought that I'd share what my own observations have.

Oh, and I think that overall, the problem hasn't been as bad with the newer versions. I have had about 100 tabs :) open in four different windows for the past couple of days, and the memory usage is about as high as when I'd have about half those tabs open in 1.0.x... (no, I have not controlled for variables like how memory/graphics intensive each page is, so this is more of a general feeling than anything precise)

Posted by: Kai at February 14, 2006 5:00 PM

"I wish there was a way to cause firefox to ignore cache headers and simply pull a disk cache up when the back button is used.. ..It's too bad that Firefox seems to pull a fresh copy off the web server every time the back button is used."

Is there a way to hack Firefox so the back button is fast like Opera?

Posted by: Zeke at February 14, 2006 5:05 PM

@zeke: use proxomitron to strip that header out before the page hits the browser. currently i'm doing that combined with a disabled memory cache and firefox memory usage is staying sane. we'll see how this holds up.

Posted by: scratch at February 14, 2006 5:08 PM

As I mentioned in two bug reports, the tool you want your end users to use for getting more info on memory leaks needs to be user friendly. you should seriously consider coming up with an extension that functions to monitor memory leaks.

Posted by: towsonu2003 at February 14, 2006 5:17 PM

That's great that firefox caches pages. And its great that they have done/know about the research that says 39% of page views are from the previously visited 10 pages (so all those saying they personally don't use that feature should defer to the research IMO - good design follows usage research, not individual anecdote).

What I don't understand is why it still sometimes takes so long to redraw a page when the back button is pressed. To me, back means, go straight back, but for some reason, Firefox seems to sometimes recheck the page, which introduces a network delay. If it really has to do that, I think it would be better to redraw the cached page first, then replace it with any changes once they come through if necessary. It would make it seem much faster.

Posted by: Xoc at February 14, 2006 5:18 PM

while you're fixing this so that less memory is being used by opening up a new tab and typing in the url bar "about:config" search for some other hacks that will speed up your browsing. Some stuff like network_pipelining and increasing it's value, I don't remember exactly, but search for 'em.

Posted by: hutch at February 14, 2006 5:47 PM

Sounds good to me - except for one thing. The table of MB RAM vs. cached pages is specious. We're caching HTML pages here, not full-length movies. There's no reason for the cache allowance to be so large for even a single page. So there is a memory leak - but one developers have documented and chosen to ignore.

Posted by: August at February 14, 2006 5:48 PM

@august: you're misunderstanding the table. it's saying that, for example, if you have 512MB of RAM in your computer, firefox will bfcache 5 pages. it's not saying those 5 pages will use 512MB of RAM, and if they do you've certainly got a problem.

Posted by: scratch at February 14, 2006 5:57 PM

Couldn't you save the rendered document to the hard drive? Surely loading that from the hard drive as one big file would be faster than the swapping caused by using such a huge amount of memory.

Posted by: Anthony at February 14, 2006 5:58 PM

Complaints about the Big Firefox Memory Bug predate bfcache, though. I don't think bfcache is the ultimate source of the problem...

Posted by: MechR at February 14, 2006 6:26 PM

The "memory leak" I complain about isn't a simple matter of Firefox getting excessively large (well, I do complain about that). My MAJOR complaint is that it frequently gets into a runaway memory grab loop where it goes from a "mere" 800 megs to 1.5 gigs in 30 seconds or less, before the oom killer gets to it.

Posted by: Timothy Miller at February 14, 2006 6:34 PM

Could it be that when browser.sessionhistory.max_total_viewers is set to -1,Firefox calculate the amount of free memory(not the total memory)and decide how much memory it should use for bfcache?It might explain why when a tab is closed,no memory seems to be released,Firefox just reserve the freed memory for other tabs.

Posted by: justkeeper at February 14, 2006 7:18 PM

Why not use a page size variable, instead of a page number? Instead of 8 pages, x number of megabytes total page(s) size.

Posted by: Andrew Shaw Care at February 14, 2006 7:21 PM

Guys, remember: unused RAM is wasted RAM.

Maybe there are other programs I'm running at the same time.

Posted by: ralphmerridew at February 14, 2006 7:53 PM

Why cache in memory?
Caching to disk (like other browsers) would perform just fine.

Posted by: Jason at February 14, 2006 7:58 PM

To all the people who keep mentioning Opera: Please cease. If you like Opera, please use it without comparing it to Firefox. Opera is the pretty sports car that works only on the highways. Firefox is the burro that can take you anywhere you want to go. The two products are different. You are comparing apples to oranges, despite what you may think. Opera, despite being years older than Firefox, still cannot render thousands of sites worth a damn. It even borks Yahoo! Mail badly, something even Konqueror doesn't do. Opera still cannot work with the vast majority of online bank websites, making it effectively useless to me. Get a grip, people. If you like Firefox, quit moaning about it. The same people who moan are the same people who are not volunteering to write code or documentation, or test bugs out for Bugzilla. If you complain, be prepared to act on those complaints in a positive way. If you want a better Firefox, help make it better.

Posted by: Rob at February 14, 2006 8:17 PM

This can certainly be regarded as a security flaw. A friend of mine kept a private blog of which she didn't want me to know about...

One time, she needed to make a post on her Blogger blog... so I lent her my laptop, and I also pointed her to use Firefox.

I guess that Blogger doesn't use https:, because I was able to go back to her Control Panel, even though she had clicked on 'log out'... and because the Blogger interface has those direct links ('View Posts')... I was able to figure out her address.

So, you see... there are vulnerabilities...

Posted by: rolandog at February 14, 2006 8:22 PM

Argh, this doesn't explain why the past releases have suffered from the same problems.

Oh well. My beloved Firefox might catch up to Opera again someday.

Posted by: Zain at February 14, 2006 8:23 PM

Slashdotted with a completely deceptive title. How typical...

Posted by: Anonymous at February 14, 2006 8:26 PM

I have 3 firefox(1.5.0.1) windows open
1 has 6 tabs
2 has 5 tabs
3 has 1 tab
task manager memory usage = 63.4M

Posted by: Kfazz at February 14, 2006 8:28 PM

the folks over at opera keep their fast back stuff on disk, this technique is slightly slower, but it does enable fast back technology without eating ram, where as firefox keeps its stuff right in the ram.

Posted by: george at February 14, 2006 8:43 PM

> ...And I have never gone 8 times back, not in the old days without
> tabs either.

I've been known to go back 20-30 steps, on occasion.

However, when I'm going back that far, I only expect the _source_
to be cached, not the rendered state. I would consider 3 pages
back to be far enough as far as cacheing the rendered state.
The source should be cached for as long as the tab is still open,
though, unless system resources are quite scarce.

On a side note, it is absolutely *vital* that to one or two levels
back more is cached than just the source, particularly if there
are forms that the user has edited. But yeah, going eight levels
back to a form and expecting the edits to be preserved would be
pretty "out there".

Posted by: Jonadab the Unsightly One at February 14, 2006 8:49 PM

Well, after all the high-end PCs that are available these days with more than 512MB RAM, its really poor to think that Fx is using more than xxMB of RAM.

I don't know if this option is available, but there could be a global variable that can be set by the user say Fx can at max use 100MB of RAM.

Posted by: Ruturaj K. Vartak at February 14, 2006 10:18 PM

I have a feeling that those people whose firefox grows to 1.5 gig overnight have either a faulty extension or they are on a site that's executing bad Javascript.

Maybe what can help Firefox is a very defensive Javascript engine that is immune to poorly written Javascript code. For example, allow Javascript engine to track the memory growth rates and to simply abort with an error when mem usage goes to a certain limit. This would have many benefits. First, the memory could be reclaimed (although not back to OS), and second, an informative popup could tell the user that the site they are visiting has bad Javascript on it, and this would place the blame on the site owner instead of the Firefox.

Without this kind of informative Javascript popup telling the user that some site is executing offensive code, the blame will of course go to the Firefox because the user isn't really going to debug the issue to see where the problem is.

It's as much a perception management issue as it is a bug issue. Let the user know where the memory leaks originate, and if the site owner is responsible and the leaky sites could be identified, then people will blame the sites instead of the FF.

Posted by: Leo at February 14, 2006 10:25 PM

Rather than basing a setting like this on "studies say", why not engineer a simple learning / self-optimizing algo that examines user behavior (# tabs, # back hits, amt ram, etc) over time and sets itself to something reasonable...

Keep an option to disable the auto-set, and allow ppl to manipulate the values as they can today...

Posted by: dxh13 at February 14, 2006 10:48 PM

What most users don't realise is the leaks can also come due to incorrectly managed/developed themes and extensions.

Personally, I have observed that FF as a vanilla browser has much less memory usage than FF with themes and extensions. Although, I could never figure one thing out. Even with your explanation of the FastBack feature, why doesn't FF free the consumed memory after windows have been closed?

And about the SessionSaver: doesn't it cache the tabs to a file on disk? Does the question of hogging memory come in?

Posted by: Shrikant Joshi at February 14, 2006 11:13 PM

Yes, I know, memory usage is sometimes related to extensions and themes and it might be related to Javascript. But it is no problem to raise memory usage to >300 MB with no extension installed, only one windows and one tab open, no Javascript and a clean profile.
Just go to a website that has thumbnails of pictures, open a hundred of the pictures or so in tabs until memory usage is at around 300 MB and the swapfile increased by 200 MB (at least that is waht happens on my 512 MB laptop). Then close all tabs except one. Memory usage might go down a little, but you end up with enormous memory consumtion. And even if you wait a few hours and have other applications runing that need memory (Photoshop for instance) Firefox does not release it.

I really love FF, I still use it, I don't mind if a feature needs much RAM, but if memory is no longer used it should be available for other applications. 300 MB + 200 MB swapfile for a single webpage is way too much...

Posted by: TfR at February 14, 2006 11:58 PM

I have also a problem with the memory usage. With a clean install, new profile no extensions i load about 20x 10MB images (for example from the galleries from dpreview.com) into tabs. (This is a dailt task for me, because i am a photographer looking on the works of other people) Memory usage goes up to 1gb mem because firefox stores an uncompressed version in its memory cache. (check with about:cache) closing those tabs does not release the memory to os, instead firefox keeps the memory allocated. so if i don't restart firefox keeps the memory and at some point the OS starts to page out. I believe this is was most people see. Surfing on graphic intense pages is at least the rease for me. Maybe someone can build a testversion of firefox with releasing the memory to the OS and those people with mem problems can verify if this helps.

Posted by: mrdom at February 15, 2006 12:07 AM

@Jason at February 14, 2006 07:58 PM
Quote: Get a grip, people. If you like Firefox, quit moaning about it. The same people who moan are the same people who are not volunteering to write code or documentation, or test bugs out for Bugzilla. If you complain, be prepared to act on those complaints in a positive way. If you want a better Firefox, help make it better.

For your information, most people cannot write code. If you bitch about them complaining about bugs in the program, it means that YOU have some very weird values. If people complain, they usually have valid reasons for doing so. If LOTS of people complain, there's bound to be something wrong with the program.
So far, by far, the most people complain about FF's memusage. Only very few are actually happy with it. This means there's something seriously wrong with it.
I've noticed it myself: I've set the amount of pages in bfcache to 0 (yes, zero, none, null, etc), and still the amount of memory in use goes up to 750 megs mem and 500-800 vm. For a browser, this amount is just simply insane, cache or no cache.
I really love firefox, it's a great browser, and I use it most of the time (only occasionally switching to IE for IE-only things).

Posted by: JF at February 15, 2006 12:08 AM

Hrm.....
Just noticed something in about:cache.

Memory cache device

Number of entries: 136
Maximum storage size: 15000 KiB
Storage in use: 25044 KiB
Inactive storage: 0 KiB

It's using more than allowed? What's the point of setting the max for this cache then?

Posted by: JF at February 15, 2006 12:10 AM

Maybe the developers should test this:
-disable plugins, javascript(all the 'memory hoggers')

Now open 400 tabs and let them load, Firefox will use about 300MB no problem here. Now close all the tabs but one. The memory useage will lower but only to about 90MB.

Now THAT is the problem most people are referring to when they talk about memory leaks.

Posted by: Ferdinand at February 15, 2006 12:25 AM

@JF Good questtion. I see this too. In my described situation max is set to 16MB and the storage in use is 800MB. Strange.

Posted by: mrdom at February 15, 2006 12:26 AM

I think the biggest problem isn't the caching of pages, but the way Firefox keeps the pictures on those pages in memory.

Take a look at this:
http://primates.ximian.com/~federico/news-2005-11.html#moz-images

Very interesting, I'd say..

Posted by: Tero at February 15, 2006 12:51 AM

Tools>Options>Privacy>Cache
Use upto xxx MB...

set it low, have no problems with cache taking up too much RAM.

Posted by: Greg at February 15, 2006 1:00 AM

"Please cease mentioning Opera"

Simple. Tell Mozilla devs to shut themselves up and do not get themselves in touch with the outside world and user suggestions.

Because people will compare features with products. Comeon, tell me who doesn't. Please don't make your post so one-sided.

It is competition that improves the quality of products. Imagine an IE-only world. There won't be an improvement.

Products that cannot keep up will fail and fade away. Take Netscape for example. IE4 won because Netscape cannot cope with the new features IE is having.

That is why Opera is adding a lot more features now. Firefox must keep up with IE7 and Opera's advancements and overtake it, only then they can rule the Internet.

Only exposure, acceptance and striving to improve will make Firefox better. Apparently this dev is hiding the fact that there IS a major leak. Opera uses less RAM and caches better.

MODS: Delete if you wish to hide these dirty facts. And bootlickers, feel free to flame me.

Posted by: lr96 at February 15, 2006 1:13 AM

Ben wrote: " You can set it to 0 to disable the feature, but your page load performance will suffer."

This is misleading, at least. Every new and non-cached page won't gain any advantage of this memory waste. You won't get any positive effect in page load either, if that site has changed, perhaps if you wrote a comment.

Deactivating this "feature" won't hit performance in most cases but save memory in every case.

Instead of cheating users by showing them old but already rendered content, I would prefer to get real faster basic rendering. Don't make the same errors like Microsoft, don't start cheating with enormous caches, and don't ignore bugs.

Ralf

Posted by: RaSa at February 15, 2006 1:20 AM

The second sentence should read:

"All versions of Firefox no doubt leak memory - it is a common problem with software this complicated _and written in a non-garbage-collected language_."

We have alternatives to C/C++ in areas where security and memory performance are important. It's just that developers seemingly think they are "smart enough" so their next project will be different from all others in that memory leaks and buffer overruns won't be a problem and can "easily" be avoided or fixed.

Posted by: Matt at February 15, 2006 1:49 AM

Yeah, thanks.

Having the "feature" really improves performance on my 512MB Mac Mini, especially when it leaks, sorry utilises 1.5GB of Virtual RAM. The entire system runs like a dog if I've had FF open for more than a few hours.

Posted by: Mike Thorpe at February 15, 2006 2:14 AM

Hmm, 1.5 GB?? Wow.
I use FF with multiple tab open always, and use it a lot. My living is part web-development, so I'd say I'm a fairly advanced and heavy user. And I have never seen FF use more than 150 MB here...And that is with 8 tabs open...for several days!

Posted by: Spinner at February 15, 2006 2:42 AM

I think Ben you should have mentioned that extensions too can cause memory leaks the latest version of Adblock Plus v6 for instance fixed a whole bunch of leaks and now memory usage hovers around 80-100MB with my 1GB box after several hours� use whereby before it would be 300-500MB.

Also about the Opera posts it probably does do a good job with this sort of thing and some of the posters are genuine but some of them are no doubt Andrew K the Opera troll who has been trolling these blogs & other forums and websites bashing Firefox any way he can. He has toned down some of his rhetoric as it made him too easy to spot but I wouldn�t be surprised Ben if you check the IP and see that a few of them are the same.
See more about Andrew and his antics here;
http://www.webdevout.net/forums/viewforum.php?f=1
http://nanobox.chipx86.com/blog/2005/12/re-firefox-myths.php

Posted by: Tennse at February 15, 2006 2:43 AM

Hey, what about exiting Firefox and not returning the memory to the system?? Is that a system feature too??

Posted by: chris at February 15, 2006 2:48 AM

A couple of points worth noting here:

1: Phantom Firefoxes still running after closing the browser. This seems to happen to me after Firefox has invoked Java applets. That's the only clue I've got on that one.

2: Memory leaks. Some people have them, others don't, which leads me to suspect either installed extensions / plugins or video card drivers leaking resources.

Posted by: Phil Randal at February 15, 2006 3:16 AM

I am an average user and I use the 8-step back in all open tabs. And this feature does not use any great amount of memory. It must be a kind of extension you are using that allocates memory. Right now my ff session consumes 43MB with 4 tabs open and 10 step history in each tab. That's not a big when comparing to 42 MB of Adobre Reader or 32MB of Skype or svchost.exe.

PS. Congratulations for black text on brown background when error in sending post occurs :)

Posted by: maclav13 at February 15, 2006 4:10 AM

It may improve the browsers speed, but when my entire computer is crawling due to lack of memory, it does not really do much for me.

Posted by: Steavis at February 15, 2006 4:13 AM

If this is the way you view other people who sees flaws with your software, it's no wonder Firefox has had such a great development since 1.0.

Let me say it quick and painless: Firefox memory management sucks. And no, it has nothing to do with caching. If you view in the order of a hundred web pages per day (that's not as much as it may sound) using the open-in-new-tab-key, after a couple of days Firefox is using 500MB RSS. If it hasn't crashed yet.

Yes, RSS isn't everything, I know that. And probably a lot of data are buffers and caches and whatever. But here's one basic fact: It shouldn't crash. It should stop growing, re-using old memory for tabs. Compare with Opera, which used in a similar way for weeks still stays under 100MB and crashes relatively rare.

Posted by: Jonas at February 15, 2006 4:14 AM

In a bug report I posted several weeks ago, I described something that definitely is a memory leak:
Memory usage increased by 1 MB per second! Each open page was fully loaded and nothing changed, but the memory usage got higher and higher. The first time I noticed, it was at about one and a half Gigabyte before I killed Firefox.

FYI, nobody is working on this bug.

Posted by: Andreas Kempf at February 15, 2006 5:04 AM

Could someone make a simple extension, that would track the number of open tabs, cpu usage, memory usage and names and versions of installed extensions. All this data (with no privacy violating stuff like web sites visited) could then be sent to a server collecting statistics, for example every 5 minutes.

This info should reveal, what combination of usage and extensions lead to memory problems. What do you think, has this been though before?

Posted by: ilefix at February 15, 2006 5:47 AM

My feeling is that more than likely Firefox is not going to return any memory back to the system, unless FF team switches to a compacting memory allocator, which is unlikely for technical reasons.

The best that Firefox can do, IMO, is to stop growing at a certain size and to simply NOT render certain pages, if it must, but really stop growing and tell the user that rendering a certain page will take too much memory. If it's absolutely essential that Firefox does not grow, then Firefox code can use some hardcore tactics to make that happen. But I really doubt that Firefox will ever (never say never) release memory back to OS, unless it was allocated and deallocated in a very fortunate way.

Maybe improving the efficiency of internal storage (like using compression if necessary) together with defensive/sandboxed code that would rather refuse to render and/or refuse to execute Javascript than grow in memory, might be the best bet.

Firefox should also, if possible, find a way to isolate itself completely from extensions. If extension memory space grows larger than X, then extension should be automatically disabled by Firefox with a popup to the user asking if they want to submit a bug report to the extention author. IF they say YES, it redirects to the extension homepage or something like that.

All this can help improve Firefox perception, which is important for widespread adoption. The idea is to keep Firefox free from blame and to put more responsibility on bad web page design, faulty Javascript and extension authors.

Firefox, ideally, should be like an operating system: if the extension is misbehaving, it shouldn't affect the entire browser -- it should just be jettisoned unceremoniously. If the page is going to push FF over some preset memory image size, then don't finish rendering that page, period. This might not be easy to do -- it's like developing OOM killer for Firefox (and if I understand correctly a similar feature in Linux kernel was not easy to develop so that it worked in a satisfactory way).

Just some ideas (not to be taken too seriously, as I don't intend to start a flamewar).

Posted by: Leo at February 15, 2006 5:54 AM

Use OPERA you stupid people.
Opera works great, it doesn't have this bug with HUGE memory leak when you use BACK button.
Use Opera.

Posted by: reeven at February 15, 2006 5:54 AM

It's not just the leak... it seems to have an upper limit. I have 2 Gigs of RAM... and without fail when Firefox leaks... I mean "caches" ~400MB it crashes.

Posted by: Magoo at February 15, 2006 5:59 AM

Also a crazy idea, but what if in some cases Firefox is triggering a bug in some OS level driver, like, say in a video driver? I don't know enough about the code to say this for sure, but could it be that Firefox is triggering a leak in some driver and the system is reporting it as a memory space that belongs to Firefox?

If the above is true, then again this is a perception issue...

I also agree with the person on making an extension that collects memory usage stats and phones home every random(x) minutes.

It's one thing for the developers to be confident that they've fixed all or most of the memory leaks, but it's entirely another thing to successfully manage user perceptions. Even if you fix all the leaks, you still have to manage user perception! In an ideal world it wouldn't be like that, perhaps, but we live in a world where perception often is reality -- "If it quaks like it leaks memory and if it walks like it leaks memory, it therefore means it really does leak memory." So in my mind it makes sense to make an extension like that, even if devs insist that they are happy with the dev-only pearl/javascript memory leak tool that is currently out there.

Posted by: Leo at February 15, 2006 6:04 AM

@magoo:

Well if it crashes then you are in luck! :) Use the quality assurance talkback tool to send the crash report. That way at least the fact that your FF crashed will be registered.

In my experience FF has crashed only once, in a weird way too, where I had to manually kill firefox.exe in task manager (on windows xp sp2).

Posted by: Leo at February 15, 2006 6:14 AM

I just hit dpreview.com in a tab and loaded about 10 images or so, and my FF mem image is at 65M, while my about:cache page reports:
---
Number of entries: 327
Maximum storage size: 31744 KiB
Storage in use: 31652 KiB
Inactive storage: 1903 KiB
---
Number of entries: 5243
Maximum storage size: 50000 KiB
Storage in use: 46031 KiB
---

Nothing out of the ordinary.

Again, I'm not trying to invalidate what other people are saying. I just want to show that it's not the whole world who is experiencing these problems.

Posted by: Leo at February 15, 2006 6:22 AM

Well what do you know...

I opened dpreview galleries in 7 tabs, my total FF image size went up to 66M from 65M, but...

My about:cache page now shows:
---
Number of entries: 101
Maximum storage size: 31744 KiB
Storage in use: 35989 KiB
Inactive storage: 0 KiB
---

So, I duplicated the "storage in use" exceeding "max storage size" problem. :)

Posted by: Leo at February 15, 2006 6:29 AM

the problem is when u close a tab, the tab cache does not release?
also, these are all excuses, whatever you say, the fact is not so pretty, especially when browsing pages with large amount of pictures, opera DOES handle them MUCH BETTER than FX.

Posted by: crislevin at February 15, 2006 6:42 AM

for those who tested dpreview.com: Thanks for testing. But what images did you load? Maybe I have a problem with my videocard driver. I am using FF 1.5.0.1 on WinXP

Could someone please test it with this images?

Loading this images give the following stats:

Maximum storage size: 8000 KiB
Storage in use: 243740 KiB

TaskManger show M:254 VM:263

Posted by: mrdom at February 15, 2006 6:56 AM

I agree that it should release the cached pages when you close tabs. I have never ever seen the memory usage go down... it only ever goes up and up.

It's sitting at 215MB right now. Then i close all the tabs except one... and it's still using 215MB.

It may well be a feature, but the problem is as a user, I don't care whethe it's caching back 3 or 5 or 8 pages. What I care about as a user, is how much of my resources it's taking up.

The user should be able to say, you can use x MB's of RAM for your cache, I don't care how you do it. I've got lots of RAM, I don't really care if it uses a "lot", so long as I have some say over how much a "lot" is. For me, I think 200MB is about how much I am willing to give firefox and I should be able to set that as an option, rather than some nebulous number of pages, which has no correlation to what users cares about.

Posted by: Magoo at February 15, 2006 6:57 AM

Main reason I think it is a leak is this...

Number of entries: 1028
Maximum storage size: 44032 KiB
Storage in use: 45681 KiB
Inactive storage: 0 KiB

It's says it is using 45MB, I know that when i start up, it uses about 20-30MB... so my memory usage should show about 75MB, yet it shows 215MB. So about 140MB are not accounted for. If that is not a leak, I don't know what to call it.

Posted by: Magoo at February 15, 2006 7:01 AM

Sorry, can't help myself. :) I did a little more research on the talkback page. I searched for all the FF15 talkbacks with the word "leak" in them and this is what I got:

http://tinyurl.com/77qof

I'll restrain myself for making guesses, but maybe devs will find it interesting. There appear to be about 3-4 "leak" crash reports per day. That doesn't strike me as an awefully large number, but maybe many people don't feel like sending a talkback and/or don't think of checking mem usage and putting the word "leak" into their talkback description.

It might help to add one more bit of info to the talkback report: total memory image size of FF during the crash. Right now "user comments" field is the only chance to get valuable memory usage info from a crash report, and only if the user manually puts it in.

Posted by: Leo at February 15, 2006 7:04 AM

I did a semi-controlled test with this. Numbers were almost the same with it set at -1 and 0. The report and figures are posted here. I'm still not convinced that its not a memory leak.

Posted by: Ryan Duff at February 15, 2006 7:05 AM

@mrdom,

I loaded all your links into tabs, and indeed the cache balooned to this:
---
Number of entries: 100
Maximum storage size: 31744 KiB
Storage in use: 259865 KiB
Inactive storage: 0 KiB
---

Far exceeding the maximum size.

I am going to hazard a guess (I can't resist). It simply keeps all the stuff in the tabs in memory, regardless. Consider what Firefox would have to do to comply with 30 MB max mem cache limit? The images in your links are HUUUUGGEEEE. It's quite possible that a single image can overwhelm the cache limit. If Firefox is to comply, it will have to unload everything that is not in the focused tab. That means as you switch back to some of the other "fat image" tabs, it will have to reload the image again from the web site! This type of behavior might, arguably, be worse than exceeding max mem cache size in this case.

Ok, now I have closed all the "fat image" dpreview tabs and my cache usage is:
---
Number of entries: 90
Maximum storage size: 31744 KiB
Storage in use: 26585 KiB
Inactive storage: 0 KiB
---

So it did go down nicely, at least in this case here.

mrdom, what kind of behavior would you expect from the browser, if each individual image was nearly the cache max size in its own right? I mean, what would you want the browser to do? Unload the images from unfocused tabs and go back to loading them from the site when you switch back to the previous blurred (inactive) tab? That seems insane to me, but what do you think is right?

In any case, I do think that Firefox should degrade gracefully instead of crashing, but for some usage patterns, like with those fat dpreview images, it just makes no sense to have a slim firefox memory usage. How do you expect to view those huge images?

At the end of this exercise my FF mem image is still 65MB.

Posted by: Leo at February 15, 2006 7:19 AM

Memory and performance issue on long download history.

If I download a 700MB ISO image file I dont see any problem in performance.

But if I download 50 files of 0.5MB (ie total of 25MB) Firefox (nightly also) eat up almost 100 MB extra memory. And the performance goes down, ie after a click it take much time for download dialog to show up, and download speed also reduced to half (on a 2mbps DSL).

Restart Firefox, it again consume 4 times memory for every downloaded file. And download performance is still bad. (note: normal webpage browsing is still OK)

Now clear download history and restart.

Then for another 10 files download will be fine, but later when it reaches 30 or 50 file performance again goes down.

So basically I can not keep download history for ever for future reference and tracking.

Another problem is if I use Firefox to browse JPG photos (of 8 mega pixel) stored on local disk after some 50 files Firefox says invalid image file even for the one we just saw early. Restart Firefox it will be fine for another 50 file, and again the problem starts.

(OS: WindowsXP Pro)

Posted by: BijuGC at February 15, 2006 7:27 AM

@mrdom:

I am cut-n-pasting this from the about:cache page:
---
Key: http://img2.dpreview.com/gallery/canoneos350d_samples1/originals/img_3949.jpg
Data size: 23887872 bytes
Fetch count: 1
Last modified: 2006-02-15 07:21:18
Expires: 2006-03-18 18:40:10
---

Look, 23MB for one stinking image. Those images are huge. I assume this is uncompressed size, which FF uses for performance. Compressed it is 3MB, still big. Basically, what I am saying is, for some usage patterns FF will need lots of memory. There are no two ways about it.

Maybe FF team can find ways to degrade more gracefully, to give better memory feedback to the user so as to inform the user of the real goings-on in order to stop falsely formed bad perception and blame, but I just don't see how FF can process 100 GIG of data on a page without becoming 100GIG in size, unless you use up 100GIG of disk space and constantly load/unload from disk, which arguably is just as bad as having it all in memory.

What do digital photo people expect? :) No seriously, what do you expect? You do know how big the images are if you work with the digital cameras. There is no way you cannot know. What do you think FF should do?

Posted by: Leo at February 15, 2006 7:27 AM

There are a ridiculous number of comments on this page.

Posted by: William at February 15, 2006 7:30 AM

I must really be unusal even tho I'm own the net 5-10 hrs a day. Across any of the three machines Ihave I've never noticed what is being reported -- right now I'm using 36mb-70mb which is a normal for me.
I suspect it's features or extensions combo people use that makes the difference. Also anyone consider the OS and how it handles apps memory use?

Posted by: steve at February 15, 2006 7:30 AM

@leo You got me wrong. I have no problems if firefox uses so much mem when i view the images. I have no problem if firefox says "ooooh this images are too big lets save them on the diskcache". So while viewing the images i expect firefox to take so much mem. But my stats i posted are after closeing all tabs, with a fresh install on a clean profile. So i expect firefox shrinks back to "normal size" and frees the big images in his memcache.

Posted by: mrdom at February 15, 2006 7:30 AM

In the past, I've been using a dedicated RAMdisk to store FF's cache dir to get better performance. Does this mean I should stop doing that, since it's already loading these pages into RAM rather than caching them on HDD?

Posted by: Sanjay Vasandani at February 15, 2006 7:33 AM

Try user_pref("config.trim_on_minimize", true);

See http://kb.mozillazine.org/Config.trim_on_minimize

Posted by: Bill at February 15, 2006 7:38 AM

With the latest versions of Firefox, specially 1.5, we have been unable to use it at work and been forced to change to Opera; our machines are not high end ( we have Pentium II, Celerons, non xp Athlons, etc. with 256 mb ram each one ) but were OK to do some web programming, putty to some servers, use remote desktop connections, etc.

I wish we could still use Firefox, because it is true that renders better tan other browser (altough i think this is due to programmers developing web pages specifically for IE and Firefox...), but the truth is that at least actually, Opera's engine its much much faster and lighter than Gecko's one.

Just my 2 cents.

Posted by: okasion at February 15, 2006 7:39 AM

> See http://kb.mozillazine.org/Config.trim_on_minimize

Already tried. This helps freeing up mem a bit. But once your "storage in use" goes up, this setting has no effect and the memory keeps allocated.

Posted by: mrdom at February 15, 2006 7:42 AM

Well I'm quite tired of people making excuses about this subject. Thanks for the explanation. Now lets fix it.

Posted by: LevelHeaded at February 15, 2006 7:42 AM

@Ryan,

I bet about:cache just doesn't report what we may think. For example, I don't think it reports the fastback cache size. Think about it. Even if you turn off fastback cache, you still are using the plain old cache upon which browser.sessionhistory.max_total_viewers has no effect. Doh. :) I mean FF has had mem and disk cache since Netscape days, yea?

So yes, there may still be a leak, and in fact, Ben says there are leaks in all complex software. But you are not doing a good job arguing for it on your blog.

Posted by: Leo at February 15, 2006 7:47 AM

Leo... FireFox memory usage is also ridiculous...

Posted by: Ripe at February 15, 2006 7:51 AM

At least, Firefox could cache only the compressed versions (.jpg .png) of the images which are not visible ie. images in the background tabs, and decompress them on-demand when the tab becomes visible. This way it would consume much less memory. Considering huge images above, I think that the time spent on decompressing is far more tolerable than swapping. With smaller images, it isn't SO bad if they're kept in decompressed form in the memory.

Posted by: Tero at February 15, 2006 7:53 AM

I'm sorry, when my browser is using 1GB of memory, that means that it is f*ed up.

Posted by: vbrtrmn at February 15, 2006 8:07 AM

I've been a faithful user even before Firefox was known as Firefox. Why does this blog look like this when viewed in Firefox? http://home.comcast.net/~missenid/blogdisplay.jpg

Posted by: Zizzybaloobah at February 15, 2006 8:22 AM

I wish I still had the link but I recall hearing that Gecko uses uncompressed tiles in it's memory cache. This is likely to cause serious memory usage, since uncompressed bitmap images are truly immense. I would not be surprised if storing these images in a compressed format would render all these "serious memory leaks" gone.

I don't doubt that Opera has a faster page-caching scheme. Try queuing up a couple dozen tabs and see how long it takes both browsers to handle them. However, please stop making stupid comments on boards like this; an excellent article like this deserves better than flame wars or "use X even though that is not the point of this article" platitudes. Thanks Ben, you have explained something that I wanted to know for ages.

Posted by: BTreeHugger at February 15, 2006 8:24 AM

People! How on earth is it possible that 8 lousy cached pages take up 500 MB of memory !! The stupid cache can't possible explain that staggering amount of used RAM. Just admit Firefox has serious leak problems.

Posted by: Ignace at February 15, 2006 8:49 AM

""I once had Firefox using more then 800megs of memory with only one window containing one tab open."

I'll see your 800 and raise you to, wait for it, 954MB!"

I'll one-up that. One window, one tab. Flash app. 512RAM all eaten, nearly 2GB page file. And outside of firefox I had no extra apps open.

Posted by: Kitch at February 15, 2006 9:29 AM

sranie w banie...

Posted by: voodoo at February 15, 2006 9:36 AM

I tried doing all the things mentioend above with memory tracking on and could not get over 89mb of memory usage on 1.5.0.1 with about 12 extensions. I am on win xp home with 512mb ram. My Eudora was at about 60mb with 75,000 msgs in 400 mail boxes just for a comparison. I will says the ff is always the biggest user of ram on the list. I also shut off ff numerous times during the day and shut down the computer every night.

Posted by: steve at February 15, 2006 9:54 AM

I don't care what anyone says, I have tried every fix I have found and I still end up REBOOTING my 2GB X2 4400+ every two days because closing Firefox DOESN'T RETURN THE 1.5GB it will eventually use. I have tried limiting tabs, limiting Flash sites, limiting picture sites, NOTHING WORKS. The worst thing is that I am using X64 and IE32 crashes every 5 minutes hwile IE64 has no plugins, toolbars or search.

This is all MS' fault for destroying the retail browser market.

Posted by: BaronMatrix at February 15, 2006 9:58 AM

I agree with the poster above, way above, who said BS. You guys should do spin control for Cheney.
Let's look at some simple FACTS, Opera and IE 7 Beta2 use MUCH less ram than Firefox with the EXACT same pages and tabs open. Why is this?
This is NOT a feature! Especially when my browser hangs while I'm sufing at night catching up on things. Never happens with Opera, only Firefox.
It IS a leak, FIX IT. Stop spinning it.
I actually use Opera more nowadays since it is faster, more reliable, and free now.
Thanks for making FireFox though, it is a great browser, and you have all worked hard on it. Just please be more honest with us users.

Posted by: stehpin_Indy at February 15, 2006 10:28 AM

I'm still using 1.0.6 with the following issues:
* launch without accompanying ui
* memory increase outstripping browser use
* very slow restore from minimise
With any app, I have it loaded for the minimum time necessary to reduce RAM usage because I hate RAM/page file lag.

Posted by: paul1972 at February 15, 2006 10:45 AM

I agree with BaronMatrix. Stop the spinning and fix the damn thing. Firefox is a great browser otherwise but I have to shut it down at least once a day to get my memory back. I'm running with a gig and almost have of it ends up eaten before the end of the day.

Posted by: physio at February 15, 2006 11:23 AM

Uhh, BaronMatrix, hate to tell you, but if you actually close firefox and the memory doesn't return, that's a leak in your OS. ( make sure it's really closed. ).

stehpin_Indy, if you worry about memory usage, turn the caching preference off, everyone wins.

Posted by: dantealiegri at February 15, 2006 12:06 PM

In the spirit of things, I'll raise your 954 megs to... *drum roll* 1086 megs!

This is on a single open window displaying the blank screen of a new tab!

Unfortunately, my computer only has 512 megs of ram. It was swapping at a rather impressive rate.
And this doesn't even mention that it was showing 99% processor utilization to accomplish this perhaps herculean feat. This occured to me on Firefox 1.5.0.1, though i've had similar problems with 1.7.

Firefox is an incredible browser, but it does have its bugs.

Posted by: mossadacity at February 15, 2006 12:17 PM

This is getting silly. I've now seen people blame everything from extensions and themes to the OS and drivers, javascript and now even the users themselves. Obviously your browser is just 'too jam-packed with awesome features!!!11' for users, average and otherwise.

The fact of the matter is, yes, only certain people have problems. Some people seem to have none, which is great for them, but for the rest of us its rather insulting to be blamed for something that has nothing to do with our use of the software or told that no problem exists. Every time I see something about this the responses always tend to be something along the line of 'it must be something you did wrong, because FF is the best browser eva!!!11'

Please.

I've been using firefox for a while now and have gotten incredibly sick of having to restart it every few hours under heavy use. Even the vanilla browser manages to eat up extreme amounts of memory (1.5GB+ pagefile use) after routine browsing and when I close all the tabs it releases NONE of the memory. Yeah, sweet 'feature.' When FF eats up my entire harddrive with a gigantic pagefile and makes it impossible for any other programs to access any memory, real or otherwise, I get a little pissed. There's no reason why this should happen on a regular basis with normal browsing habits. If the browser can't support my browsing habits, you don't have a very robust browser, and blaming me is only going to make me even less willing to use it.

For those who've mentioned opera, I must agree with them. Over the past month or so I've steadily begun to use opera more and more frequently because unlike firefox it won't eat up all of my memory and make my system run dog-slow. Sure, it crashes sometimes too, but at least I can recover from an opera crash in about 10-20 seconds as opposed to the 3-5 minutes I have to wait for firefox to finish crapping out and finally give back some memory. Even IE7 is more usable than firefox for me.

With the offical FF team writing off these problems as 'dumb users' I'm getting more and more tempted everyday to just uninstall FF altogether, which would be a shame. Memory problems aside it's a wonderful browser and by far would be my favourite. Of course, the memory problems are a part of the reality of FF and it makes it nearly unusable to me.

Posted by: Wayne at February 15, 2006 1:26 PM

my 2 cents:

My FF usage on several machines (all Windows 2000) with some extensions the usual load is around 50 - 60 MB.

My normal usage is about 4 - 10 tabs and two Windows (each Windows is a topic and the tabs are my browing on the topic). I normally don't use "back" more than once or twice.

Some times, with each version, I've had FF trouble from websites that start a java applet and have had to use task manager to kill it (and then usually rebooted). This is probably the most usual issue. I'd sure like a "java" block like the popup block to allow selective running of java.

A few websites have had some kind of javascript running that will cause a popup telling me that it is using huge amounts of memory. By that time my computer has a hard time repainting the screen.

I run proxomitron with default filters (except adding a few like sound to links, kill nosy javascripts, and kill onunload). There is probably some more I could do with it, but since I'm shifting to Linux I don't want to spend time on a one trick pony.

I've left FF running idle as long as a weekend and it hasn't seemed to be a problem, but then I reboot every week anyways.

And a few times FF just seems to have freaked out for no reason, but that happens when I've got several windows open with like a dozen tabs each and Windows is already under a load.

So, I can't say generally conclude that the issue is a memory leak, but it does seem to get dicey under Windows or FF are in heavy use.

I haven't used FF under Linux enough to make any kind of observation.

PS. Wow, your comment submission error page sucks for color scheme. Black on dark red. Brilliant design. (that was sarcasm, btw)

Posted by: StephenC at February 15, 2006 1:31 PM

I'm tired of programs (and operating systems) that base the amount of memory they allocate to their cache on the amount of RAM you have in your computer. Imagine if every program I ran used similar methodology. If I left these programs running, they'd consume all of my available RAM. If I have a gig, Firefox thinks it's OK to allocate 25% of that to its own cache (actually, it could be more since it's based on pages with no memory ceiling). So if I keep firefox running, and then launch another memory hungry app, I start to page, simply because firefox wants to make the back button faster. Great logic! In memory caching should be used sparingly. For large data structures like this, use a disk cache and let the OS's filebuffer cache provide the performance boost.

Posted by: Erik at February 15, 2006 1:40 PM

I don't really care what is causing the problem. All I know is that I have 8 IE7 tabs open and 3 Firefox tabs open and IE7 is taking 30MB and Firefox is taking 120MB. And I don't notice any performance difference.

This topic needs very serious attention by the Firefox development team as memory usage brings my Windows system to a standstill.

Posted by: pwb at February 15, 2006 1:58 PM

Ben,

A group of developpers would have claimed that they found a major security flaw within the page caching feature, allowing remote control in Firefox 1.5

Have you heard of this?

Ken Due.

Posted by: Ken Due at February 15, 2006 2:51 PM

Ken, do you mean what you write? It's huge! It would have been already unveiled!

Posted by: sye1567 at February 15, 2006 3:16 PM

Reminds me of high school. I was absolutely certain that each teacher assigned homework based on the assumption that we only had the one class, and would therefore have enough time to finish the work without cutting into vital activities like getting to/from home, eating, and sleeping.

Posted by: Kelson at February 15, 2006 3:42 PM

One real memory leak is that of X-server-side pixmaps. When surfing lots of image galleries, Firefox easily allocates several hundred megabytes of server-side pixmaps, which don't get freed until the browser is closed. Versions prior to 1.5 at least freed the pixmaps when you closed the tab in which they had been displayed.

Posted by: ilmari at February 15, 2006 4:00 PM

In fact, I think a lot of "memory leak symptom" actually are related to the memory cache.

For my case, I have "fasterfox" extension installed on 2 computers running Firefox, one has 1GB RAM and the other 256MB. With the default fasterfox setting, it will set the memory cache to 64MB, regardless of the amount of physical memory, which is way too high in my opinion for the 256MB machine (1/4 of physical memory). After surfing the web for some time, you will see the "private bytes" memory usage climb up to more than 100MB. It seems the 64MB memory cache is included there. However it seems not much people are aware of this issue, and they are happily using fasterfox.

Posted by: smallpotato at February 15, 2006 5:07 PM

Seems like there'd be some upper limit of memory usage, then. I use FF 1.5.0.1 on a 4GB system, and firefox routintely gets up to about 600MB of memory usage, then bogs down, goes unresponsive, then crashes.

Happens with fresh installs, no extensions, etc. Just browsing for a day or so will do it; maybe 500-1000 page loads.

-b

Posted by: aiken at February 15, 2006 5:39 PM

Being a longtime Opera user on Windows, and having recently delved into the Linux world, iV finally used Firefox 1.5 on Ubuntu.

In my opinion the 'unresponsiveness' of the tabs and back/forward, relative to Opera, is seriously frustrating.

Posted by: Matt at February 15, 2006 6:52 PM

SessionSaver is evil, remove it. I never had a problem with FF until I ran 1.5 (and the 1.5.0.1 upgrade) with SS installed. If you want the same features, plus a whole lot more, try Tab Mix Plus.

Posted by: Douglas Clifton at February 15, 2006 7:36 PM

I think all of you guys should have a look at "about:cache",there're pretty many interesting things there.

Posted by: justkeeper at February 15, 2006 8:07 PM

I think the simple fact that closing tabs does not reduce memory usage its something it should be looked upon.

Also I dont understand the logic behind browser.sessionhistory.max_total_viewers preferences: do you need 64-128 Mb to cache each back-forward rendered page?

Posted by: PA at February 15, 2006 8:38 PM

No extensions, max_total_viewers and max_viewers set to zero, fresh start of firefox, clean profile, mem usage about 29M, after opening several windows and tabs, about 300M.

This is clearly a firefox problem, and it is not a feature. When the usage hits 200M or greater, firefox slows down and becomes prone to crashing. Even if this is caused by a 'legitimate' memory operation, it still needs to be fixed so that it does not detrimentally affect the system (or firefox itself). We're not complaining because it feels good, we're complaining becuase firefox is CLEARLY affecting the system in a detrimental fashion, and that should NEVER happen. Even Internet explorer, the worst browser on the face of the earth, does not cause this kind of memory usage problem. You need to address this issue, not make excuses about it.

Posted by: Gorbnartz at February 15, 2006 8:41 PM

Feature? No, flaw. I know FF developers have a better understanding of what's going on and why the memory abuse can be considered a "feature" but get out of development-land for a bit and come back to the real world with the real users. This is a serious flaw.

Posted by: BobHope at February 15, 2006 11:28 PM

memory problems were solved here
with this in about:config
browser.cache.memory.enable false

Posted by: Joe at February 15, 2006 11:52 PM

I am not sure if this is arrogance or ignorance or just me misreading the whole post but it really does tempt me to switch to Opera. Having used FF from the 0.2 days, I would love not to have to do that but when a developer says something like:

"What I think many people are talking about however with Firefox 1.5 is not really a memory leak at all. It is in fact a feature."

what I read into it is "You users are dumb fools who don't know what you are talking about. I helped write the software and (hence?) there are *no* memory issues with the feature. Nope, you don't matter."

Posted by: Srijith at February 16, 2006 1:38 AM

All you Opera shills that commented in this thread will be interested in knowing that just because of your misleading spam and insults I will NEVER use Opera.

As for the memory leak, I don't get it except for the mysterious 90MB of use once Firefox loads a couple of pages. It never goes back down to the original 30MB or so. *WHAT* is it caching?

Posted by: Osama Bin Kenobi at February 16, 2006 2:54 AM

Like some other commenters I am a tab-heavy user. With versions older than 1.5.0.1 I found that opening a lot of tabs, closing, opening more dragged my memory down.

Small test with the firefox instance I have open now. Memory usage was 50 MB, opened a bunch of tabs, got to 85 MB and then closed them back to the tabs I had open (4), memory usage didn't go down further than 70-75 MB (seems to fluctuate).

Makes you wonder where the 20-25 MB went to.

Also, testing with Purify doesn't make you happy, apparently the Javascript support part leaks like crazy, and funnily enough, all bug reports containing purify logs and the likes are sitting idle for long, long periods inside the Bugzilla database.

Posted by: Jeroen Ruigrok at February 16, 2006 5:01 AM

All of you who blame Ben for seeking excuses for the Firefox memory leak should read the article twice.Has he ever said that Firefox has no memory leak problems? The second sentence he wrote starts with "All versions of Firefox no doubt leak memory ".He was just giving suggestions about a possible solution to some of the users' problems.What's wrong with that?

Posted by: justkeeper at February 16, 2006 5:24 AM

I just have one serious question about memory usage for all you Firefox fanboys: if Firefox is so great, why can't it bring me my coffee in the morning, like Opera does? Or wipe my ass after a particularly nasty dump like Opera (and, sometimes, Andrew K aka Mastertech http://www.populartechnology.net/) does? Stop avoiding the real issues and answer these serious charges.

Andrew the 3rd

Posted by: notlikely at February 16, 2006 6:03 AM

This 'feature' has been a problem for me for some time. At one point I made the mistake of adding a new partition and not updating my fstab (we're talking Linux here) resulting in no swap partition. This meant that as Firefox built up its memory usage the physical memory would top out and my XServer would be killed automatically.

I have reconfigured now (I'd been lazy before), but Firefox will still build up memory usage to a ridiculous figure. I have closed tabs down to a single tab and seen no improvement in memory usage. I have then closed Firefox completely and watched my swap usage drop from close to topping out on 512M to 32M, and my physical memory drop from close to topping out on 1G to around 200M - so not too far off 1.5G of usage!!

Feature or not this is not working in the best manner. I will be trying this 'fix', but for less technical users and those that just stick with the default installs something needs to be done as the number of people using Firefox increases. Perhaps an option somewhere should be added, and I would suggest disabled by default.

I've noted the amendment that details 8 pages across all tabs, but I would consider that either the original statement was correct, or there is something else in there. Oddly I've not noticed the problem with the Windows version, but then I'm far from being a heavy Windows user and this shows up most when I've been using Firefox for most of the day or longer - I can't stand using Windows that long in one go :)

Posted by: Paul Tansom at February 16, 2006 7:02 AM

I have seen memory usage for going high, when i open up a page which uses lot of ajax features for e.g. www.netvibes.com or Google customized page like www.google.com/ig with lots of RSS feed on the page. Every time you reload the page, the memory usage goes up and never goes down even if you close the page. This is despit the settting browser.sessionhistory.max_total_viewers = 0 I think somehow the httprequestobject consuming lot of memory.

Posted by: Ketan Kothari at February 16, 2006 8:10 AM

Obscurely enough, especially for those that claim to have had previous wisdom and throwing the '�diot' idiom around (and surely not knowing much), this browsing feature has only minimally changed the memory usage since e.g. 1.07. The last record observed is 310mb in 1.5.01. Where in past minimising ffx would return a lot of that back, the 1.5 and up does barely.....this I consider wholly incorrect. If I minimise it, since it takes ages to load compared to IE (6 or 7) or Opera, it should be relegated to disk page +/- features like running the radio e.g., but surely no need for keeping all those pages ready in Ram. Thus, there should be some memory options.....the tip on the full cached pages in ram is great and changed it to 3, for that is practically how far I usually go up and down...else, I think a more optimised use of the classic page cache (or buffer as the moz boys call it)....I barely see difference with Opera going up or down, thus there is an extremely and not to be wiped off the table question!!!!! BTW, how do we get from 64mb with 1 page render ready to 512mb at 5???? Also, comments like 'unused ram, is wasted ram' is an another 'brillaint' comment....maybe one from a browser/gamer only user? I agree with the real question posed several times and still left open: what's on and when is the leaking remedied? If ever there is a wish to enter the big stream business world user realm, where browsing is not the only thing done, it needs resolution. Today, i think its great for home, but i would not entrust it onto a business PC.

Posted by: sekerob at February 16, 2006 10:59 AM

In my opinion, this is still a memory leak, albeit in a different sense. If I close a tab, I don't expect to be able to get back to that page without a fresh page load. I'd much rather see a session-per-tab algorithm, with separate caches. Then when a tab is closed, no memory associated with that tab remains allocated. That seems to be the source of the confusion - people close a tab and memory is still used by cache for pages that are presumably done being viewed. The algorithm needs to change to match the user paradigm.

Posted by: Andrew at February 16, 2006 11:19 AM

>> BTW, how do we get from 64mb with 1 page render ready to 512mb at 5????

This was explained at least twice in these comments. As well as in the paragraph 0.5cm above that table. You _can_ read, can't you?

Posted by: ant at February 16, 2006 11:25 AM

I tried setting the
browser.sessionhistory.max_total_viewers
to Zero.
Then I closed firefox (1.5.0.1 Windows XP) and opened a bunch of windows and a whole bunch of sites in tabs. Memory usage = 252MB.
I closed ALL the tabs except one (which was blank - no url). Memory Usage 127MB.
Better, but still no cigar. What's it holding that 100MB for? When I open Firefox (empty url) it uses 29MB. (Which is still inane, but acceptable). That 100MB is not a "feature"
Letting Firefox suck up memory without bound is not a feature. It's called SUCKING.
I use Firefox, but I'm actually hoping IE 7 is good, because IE 6 uses FAR less memory than Firefox. And it performs better on many pages too.
I'm no MS Lackey, but I think the Firefox guys forgot when they branched off of the Mozilla suite they were going to make something light weight.
Remmber. Light weight? That means you don't suck up memory infinitely.

Posted by: Max Rockbin at February 16, 2006 11:47 AM

Actually "light weight" means not supporting two whole image formats to make the download 50KB smaller.

Posted by: ant at February 16, 2006 12:02 PM

Okay, I'm not going to debate with 'you can read' commentators...adding from 256mb to 512mb limiting to 2 extra pages gives away a scary indication of the memory hog hiding within? Why do I think that regardless if one calls it tabs or windows, in reality each tab loads a complete Firefox (I see it being done all the time, new window opened and then converted to a tab in the original window). Why do I think that the 'tab close undo' is (partially) responsible for not giving back memory? Cogito ergo sum.....reading between the lines can be learned too!

BTW I hard set the pref from Ben to 3 after which memory usage dropped to 134mb, without closing ffx! Now that was a very useful tip not impacting my browser habits AT ALL!. Think the options screen definitely needs a 'memory management' tab...I'm sure someone is going to tell me there's an extension for that ;>)

Posted by: sekerob at February 16, 2006 12:13 PM

Firefox 1.5.01 Release Notes: http://www.mozilla.com/firefox/releases/1.5.0.1.html

Here's what's new in Firefox 1.5.0.1:

* Improved stability.
* Improved support for Mac OS X.
* International Domain Name support for Iceland (.is) is now enabled.
* Fixes for several memory leaks.
* Several security enhancements.

It was a memory leak, thankfully the mozilla dev team plugged the main leak, no more whitewash mmkay?

I experienced up to 500Mb of memory useage doing but browsing, blaming extentions is stupid, they are just UML code, UML code is controlled by Firefox UML core, and therefore Firefox would be to blame even if extentions were triggering leaks, which they clearly are not since I experienced leaks with or without extentions.

500mb would cache millions of pages, but it doesn't release them, therefore it was a leak.

Posted by: Aidan at February 16, 2006 6:03 PM

I've used Firefox since 0.8. I wrote a couple of extensions for it, one of which is on UMO/AMO. I'm posting from Opera.

I browse a lot of large, high-quality images (~300kb-1mb) in 10-20 tabs and Firefox dies after 30 or so images opened individually in tabs then closed, requiring a browser restart or even OS restart.

My computer is not new, but certainly not ancient. P4 2.0 512 MB, with 2 drives with a fixed-size pagefile on each for a total of 1678 MB pagefile, or ~2 GB total virtual memory.

The other day was the worst: Firefox died with a "low virtual memory" error because it had filled all 2gb (yes I said gigabytes!) of virtual memory on less than 20 images currently open in tabs, after viewing and closing many photos as I stated above. 20 x 400kb = 8mb. Ridiculous that it would take up 2gb.

Your suggestion that the bfcache causes the memory leak is wrong in my opinion. It's really starting to bug me that this bug hasn't been taken seriously. It's the biggest problem with Firefox and will cause many more people to switch if it's not fixed. I remember the same behavior in previous versions, so this is nothing new, but my browsing habits have changed since 1.0PR or earlier, so I can't tell if it's gotten worse.

I never thought I'd use Opera, but I'm using Opera for my photo work for now and Firefox for everything else. I'd rather have just one browser for everything.

One thing I noticed was that when you open image pages (such as Imageshack's; image + ad on a simple page) in tabs in Opera, Opera apparently doesn't keep the images for tabs you're not viewing in memory. You can actually see it loading from disk or the internet when you switch to that tab long after the page has finished loading in the background. I'd rather have that wait than have Firefox keep everything in memory just to crash and burn after less than an hour of image browsing.

Posted by: benthere at February 16, 2006 7:46 PM

I did as advised and my Firefox still has a memory leak. I checked it as soon as I restarted and it was at 2800 K, now as I write this it is at 36,952 and climbing. I set the value to 0 and the memory is still leaking. I think the issue runs deeper than you make it out to be.

Posted by: nykrindc at February 16, 2006 7:59 PM

oh, i use opera the faster browser on earth...

that should spare me from all of this trouble..

cheers!!

Posted by: vince at February 17, 2006 1:48 AM

As per my findings previously, using Ben's pref mod set at 3, my ffx mem use sits hard between 134 and 140mb including a tv stream from the winterolympics (sorry, but the site requires to be run in and thru a IE TAB 1.08). ALSO, for those open to try it, FFX responsiveness has in fact SUBSTANTIALLY IMPROVED....so much for full render page caching !!!!!!

Posted by: sekerob at February 17, 2006 1:53 AM

I find this blog entry and it's comments quite funny. If you are some sort of programmer wanna be you'll put up with crap like slow performance and "memory leaks", but for the average Joe that comes along to try out FF, it's performance SUCKS! It took me weeks of screwing around to get it to work, period. Between that back page cache issue and some purely rotten memory hogging extensions FF was worthless. It's easy to think everyone will run out and buy the latest, largest RAM, fastest computer out there so they can run FF, I sure won't.

I guess you get what you pay for in life.

Posted by: Sooty at February 17, 2006 5:16 AM

No matter what, memory leaks are NOT inevitable! I designed and built C++ frameworks for very large-scale manufacturing systems that run 24x365 (they run most semiconductor fabs worldwide) that don't leak memory, and these are WAY more complex systems than something like Firefox. In fact, I developed a reference-counting GC for the framework that allows application developers to never use operator delete at all and still not leak memory, yet perform well in very demanding situations. So, the excuse about memory leaks in an application like Firefox is specious, in my professional opinion.

That said, my experience with Firefox, though positive on the whole, is still sprinkled with frustrations on these anomalous behaviors and occasional leaks. I have to shut it down on a regular basis, otherwise it tends to go into lala land and eat up a fair chunk of RAM. If the manufacturing applications based on my frameworks did that, our customers would take us out to the proverbial woodshed and tan our behinds!

Posted by: bboyle at February 17, 2006 7:13 AM

Could this problem be stemming from the OS? Windows has always been plagued with memory leaks. MS tried to deal with the issue with XP; however, it's still far from perfect. Perhaps FireFox's use of a RAM cache is only magnifying a situation caused by the root memory manager.

Just a thought...

Posted by: No Nonsense at February 17, 2006 7:57 AM

Ben,

For a very graphic demo of just how serious the memory leak is, use Firefox to go to news.yahoo.com and just leave it on that page for a few days. Then, in Windows Task Manager, periodically check the amount of memory dedicated to Firefox -- watch it grow! After a few days, it will be well over 1GB! Every time Yahoo auto-refreshes the page, the memory usage bumps up.

When it can safely be left on this page w/o trying (Borg-like) to assimilate your entire PC, I'll be satisfied.

Regards,
Andy Allen

Posted by: Andy at February 17, 2006 8:29 AM

What language is it written in?

Posted by: Varghese at February 17, 2006 8:49 AM

Andy: I agree with you; I see from task mgr that the memroy keeps increasing without any activity in the browser. This is my kids' PC that has Win2000 and 128MB RAM and FFX sometimes holds up the PC. If the mem problem is not fixed then this browser will not take off with the regular users. How can I ask my 10yr old to use FFX instead of Exp?

Suresh

Posted by: Suresh K at February 17, 2006 8:51 AM

"All you Opera shills that commented in this thread will be interested in knowing that just because of your misleading spam and insults I will NEVER use Opera."

Good for you. Don't use it. I could care less. If you're too ignorant to use a better browser then that's your problem.

I used to love Firefox. Back in the Firebird and Phoenix days. I grew sick of the memory issue (call it a 'leak', 'feature', I don't give a crap - it's a PROBLEM) and stopped using Firefox. I went back to IE 6 sp2 for awhile before trying Opera again. No memory PROBLEM there boys and girls. Fix the one in Firefox...I may come back again. Until then - keep coming up with excuses for the memory PROBLEM until you're blue in the face - IT'S STILL A PROBLEM.

Posted by: Nick at February 17, 2006 9:04 AM

Why not simply add an option to clear cached data upon closing tabs or a button to do so one historical page at a time? Personally, I don't see this as an issue.

Posted by: Steve at February 17, 2006 9:05 AM

I too am upset about the excessive memory consumption of firefox. Rule #1 has always been: program correctness first and foremost, performance is important but secondary. The other suggestion is to rewrite large parts of firefox in the Ocaml language; in retrospect you'd realise it was the best implementation decision you ever made.

Posted by: Slavcho Nikolov at February 17, 2006 9:14 AM

I'm no techy like the rest, but I was really p-o'd when the whole thing became inaccessible to me. It reports "Server unavailable". probably some simple reason, but unavailable is still unavailable.

Posted by: sgtsnider at February 17, 2006 9:25 AM

sore spot, huh?
memory is my number one complaint on a browser i really want to love. (and do love in other respects)

how about putting new features and integrated RSS and stuff like that on hold and fix basic infrastructure issues like this for a new version of the browser. if all the developers concentrated on these sorts of things for a couple of weeks it would speed up regular development anyway, since you'd end up with much cleaner code! and that goes triple for thunderbird!

matteo

Posted by: matteo at February 17, 2006 9:26 AM

I'm using the K-Meleon browser now because of the Firefox memory issues.

Posted by: K-Meleon at February 17, 2006 9:33 AM

First of all, all firefox developers are working for free. They do not make money on it. If they have times, they will help to fix the problems. These developers do have family to take care such as wife, kids, houses, yards, etc. It is not easy as you guys on the web to say as easy as it is to fixed. As many good programmers on the web, why they are not to take on this issue. Simple way to say, they are working for money not free all the times. Sometimes these ff developers have to work on the project with his or her company as especially these projects are due and developers do not care about firefox when his or her project on the line. No one is out there trying to develope stuff for free. If they come out with good stuff, they will try to patent it so no one can steal it. They could make more money then they are doing for free.

Posted by: lhtran at February 17, 2006 10:29 AM

I downloaded Firefox after the first major release and it was very buggy and kept crashing so I stopped using it.

I downloaded Firefox 1.5 several weeks ago, and still didn't like the performance. How was I supposed to know I needed 1 to 2 gig of RAM to run a browser? I'm certainly not doing any 3-D modeling or advanced graphical work! I'm just one of millions of people who want to browse the Web.

So, all the bragging about how many people have downloaded Firefox isn't as relevant as how many people are actually using it. Outside of programmers and the Slashdot crowd, I wonder how many users of Firefox are really out there?

Can I call an 800 number for Firefox support? Oops � no, there�s no customer service because all the programmers behind Firefox are �volunteers�. I know, I know � I should spend hours surfing through forums to get the answers and support I need.

I�m glad some people are willing to give their time away because they resent that Bill Gates is a multi-billionaire, but thank God the local plumber, auto mechanic, and so forth all charge for their time so I can hold them accountable.

Posted by: Frustrated at February 17, 2006 10:39 AM

Is it so hard to restart Firefox once in awhile? I don't understand why people say this is such a big deal.

I understand that it shouldn't happen, but people shouldn't be harping on the developers to fix it and then also get mad at the developers for not doing frequent releases.

Firefox rocks!
----------
-Ryan
CyberNet Technology News
http://www.cybernetnews.com

Posted by: Ryan at February 17, 2006 11:04 AM

On average at least once a week, I get a memory corruption resulting in a Blue Screen of Death. Could this be due to the memory leak and cache problem of Firefox?

Posted by: Ron at February 17, 2006 11:09 AM

This is the first I've heard of the about:config page. Good to know about it.

Oh, and my browser.sessionhistory.max_total_viewers was set to 50 by default!!!!!

Posted by: C.R. at February 17, 2006 11:09 AM

With respect to the comment:

"All versions of Firefox no doubt leak memory - it is a common problem with software this complicated."

Memory leaks are not caused by complexity. Memory leaks are caused by sloppy design/coding practices.

Posted by: lefty at February 17, 2006 11:18 AM

What are we all using to see memory usage? I have Windows Task Manager but it's Win98 and Task Manager isn't good for much.

FF is definitely a huge memory pig. From this thread I now know I'm not imagining it. I have no extensions installed, so they're not to blame. Netscape 7, Opera 8.5, and my ancient IE5.0 don't have these problems, so it's not the OS, crummy though that may be. I use one to three dozen tabs routinely, and after the system starts crawling the only fix is to shut everything down and reboot.

FF has other problems, but at least it hasn't spontaneously lost all my bookmarks - not lately, anyway. It freezes when saving anything, and won't answer the keyboard when I want to abort an operation, such as waiting for a page which is taking forever to open.

Posted by: bigdirigible at February 17, 2006 11:42 AM

Memory consumption, performance and stability need to be the highest priorities for Firefox 1.6.

Otherwise, I think we will see going back to IE now that v7 has tabs, Google search, etc.

Posted by: pwb at February 17, 2006 12:37 PM

My system has 620 Mb ram. So, I expect firefox to cache 5 or 6 pages from above table. Given the websites I visit, each page size Even if the developers argue its some graphics that got cached... i dont want that graphics to be cached.. what i really want is when I fill a form and have to go back I should not lose what I typed in. Pls just cache the text. My internet speed is good and I dont mind spending extra 0.5 second to redownload the graphics or read it from the harddisk. When FF is using so much memory all apps get slow and reponse time is more than 0.5 seconds sometimes and that hurts..

in short ff1.5 caching is no good.

Posted by: vg at February 17, 2006 12:59 PM

oops.. this server cheats.. my message was supposed to start out like this..
My system has 620 Mb ram. So, I expect firefox to cache 5 or 6 pages from above table. Given the websites I visit, each page size less than 5k size. However, FF 1.5 starts out with 25-40Mb memory usage and grows to 70Mb. While FF1.0 never took more than 30Mb. Go figure why 6 HTML pages occupy 40Mb.
Even if the developers argue its some graphics that got cached... i dont want that graphics to be cached..

rest same as previous post

Posted by: vg at February 17, 2006 1:06 PM

To those who are defending the Firefox team:

The reason we are mad, or a bit upset is not because we expect these guys to labor on end without pay or rest, but rather because we've come to expect quality work from Mozilla. That is what Open Source is supposed to do, create better programs than companies like Microsoft. I use my firefox everyday, and although it is buggy I wouldn't think of switching to Opera 9 (just don't like the the way it works, I don't know but it just doesn't feel right, somehow) or IE (with or without tabs), but I do expect the best from Mozilla and the poeple who spent so much time working on Firefox. We appreciate it alot, but if there is a problem with it, we expect you to fix it. Why? Well because Mozilla has built that reputation for itself, as the anti-microsoft. If we accept less, we become less, and it won't take to much time for another upstart browser to kill Firefox and take over as the only alternative to IE if we let that happen.

Posted by: nykrindc at February 17, 2006 1:20 PM

I see the memory usage problem as well.

I'm running 1.5.0.1, currently with no extensions even installed, the browser.sessionhistory settings set to 0, and don't open new windows or tabs, just browse in the same window.

After about an hour, memory usage went from about 28-29M to better than 320M. This is either a genuine memory leak (or set of them), or the feature you speak of is not behaving itself and perhaps also ignoring the config settings.

And those who say that our reports of this problem is causing some sort of disrespect to the Firefox programmers need to get over it.

First, reports of problems with a program are often the only way for that problem to become visible to the developers, allowing it, in principle, to be fixed. There is an overwhelming amount of evidence, on this post alone, that there is clearly a real problem with the way that Firefox handles memory. The real disrespect here is being caused by those who choose to avoid the issue or make excuses for the problem.

As for the time and resources of the developers in question, it's clear that they apparently have sufficient time to code new 'features', but when they're asked, by their users (without whom there would be no point to Firefox), to address clear and obvious program problems, it suddenly becomes too onerous to deal with.

It makes a great deal of sense to suggest that the Firefox team should set aside an update release where the entire effort is dedicated to addressing these issues with memory usage and stability before spending time on the next set of features.

And while it may not be a huge deal to restart Firefox from time to time, it SHOULD NOT BE NECESSARY to do so.

I use Firefox pretty much exclusively, and it's a great browser with a lot of potential, but it's not enough for Firefox to be 'good enough', it needs to be MUCH better than the alternatives, otherwise, there's no real reason to use it.

Posted by: Animatronic at February 17, 2006 2:18 PM

Would it be an option to set browser.cache.memory.capacity from -1 to lets say 64MB?

Posted by: Mathias at February 17, 2006 2:29 PM

"What I think many people are talking about however with Firefox 1.5 is not really a memory leak at all. It is in fact a feature. "

Huh? Firefox is caching up to 8 pages in memory?

Am I crazy, or is there something called Temporary Internet Files where all the HTML, images, JS, CSS, and other related files are saved. So, if I've already downloaded a page with lots of large images, why does my browser need to store those images in memory? Up to 1 - 4 GB of memory being taken up by the freakin browser!?! What if my page has a giant Flash movie that's downloaded ... everything on my last 8 pages are saved in memory!

C'mon guys, this needs to be fixed. I'll start using FF again when these memory problems are taken care of.

Can't wait for IE7 to be released....

Posted by: Huh? at February 17, 2006 2:41 PM

Yesterday when FF's memory usage on my machine got to just under 425MB, I decided to shut all instances of FF down and start it again to clear it out because browsing and everything else on my machine had begun to severely slow down. I've got 1GB memory on my machine and the max_total_viewers=-1 (default)

OK. So I've got 8 pages that are cached (I assume that's per tab too). BUT A HALF A GIG FOR A BROWSER???? Come on people! I've got software development tools on here, including Visual Studio .NET that, even on its worst day, doesn't consume that much memory.

I understand keeping some forward-back pages in cache, but for cryin' out loud, give back that memory if/when I close the freeking tab!

Posted by: rlb at February 17, 2006 3:00 PM

I've got to laugh at most of this... I've never had firefox take up more then 80mb of RAM. Granted I run Cacheman (a memory mananger since Windows Memory Management system has never worked well) I normally have 2-8 tabs open and never have a problem... Every program that interfaces with Windows Memory Management will leak... that's why you get a 3rd party one. I'm running 8 Extensions (Adblock, No Script, Flashblock, Forecast Fox, Nuke Anything, IE View, and Copy Plain Text) atm I've got 481 MB free and my PC has been up 3 days obviously I've been browsing during this time period. ATM firefox is 49 MB and seriously RAM doesn't cost much anymore so it's funny to see people griping about it ;)

Posted by: Indomidable at February 17, 2006 4:56 PM

Sorry, 'Indomidable' (a less appropriate handle has yet to be conceived, and you cannot even spell it correctly).

I've used Cacheman, and it:

a) does not manage memory any better than the default windows memory manager, and

b) does not have a substantive effect on the memory usage of firefox (it still grows unremittingly, regardless of what manages memory).

Shill your wares somewhere else.

Additionally, there's been a significant number of comments regarding the value of 'used' memory, i.e. 'unused ram is wasted ram', and 'ram is cheap, so who cares?'. Only developmentally disabled morons make those kind of claims. Memory tied up by one program is unavailable for use by other programs, and a well behaved application does not reserve (or use) more memory than it honestly needs to perform the task it requires. And there is NO legitimate circumstance where a browser should EVER use 200M or more of memory, PERIOD. Bad memory management detrimentally affects EVERY OTHER application on the system at some level or another. That said, I would be less aggravated by the memory usage of Firefox if said memory usage did not detrimentally affect the speed and stability of the browser and the system.

Posted by: Gorbnartz at February 17, 2006 10:58 PM

A couple of points:

Ben Goodger:

studies show that 39% of all page navigations are renavigations to pages visited < 10 pages ago, usually using the back button

Where these studies on tabbed browsers?

IMO one usually has a good idea whether one may have to go back to a page one has already opened, and, if I'm using a browser with tabs I make sure I keep any such page open in another tab (or bookmark it if I 'm not going back to it soon). I, therefore, think that this caching is a bad idea for those of us who do tabbed browsing.

Ken Saunders:

open a bunch of tabs, then close them all, the memory usage doesn't go down much because you've just populated the memory cache)

I get this too (on 1.5.0.1, 1.8.0.1 (i.e.:1.5.0.2) nightlies, trunk nightlies, and other recent versions). There should be some way to make sure that Firefox (regardless of any other settings) never uses virtual memory when it doesn't absolutely need to; Fx definitely should not be using more RAM than my physical RAM which it does if it has been running for a day or two in MS XP.

BTW, I usually use GNU/Linux (on the same system) and I don't get this anywhere near as bad, although it is still pretty hogging. Because my GNU boot hard drive has died so I must use MSW XP, I seriously think I'm going to have to replace Firefox 1.5.0.1 with Phoenix (which never had these problems).

Posted by: Joe Blakesley at February 18, 2006 7:47 AM

Why do Firefox developers assume they have the only viable browser on the market?

Power users are starting to look at Opera as an option despite their proclaimed love for Firefox. And IE7 is just around the corner...

Stop making excuses and FIX THE PROBLEM. 289mb for 8 cached pages?! Who are you fu*king kidding?

Posted by: defbringer at February 18, 2006 9:18 AM

I just did some simple testing using IE, FF and Opera. I started each browser and loaded this page and refreshed it a couple of times as I noted the memory usage.

These are results of it (memory usage in kbytes):

IE: 17.184->17.116->17.216->17.184->17.200->17.112->17.068
17.176->17.152->17.056->17.188->17.120->17.076->17.188
17.204->17.236->17.168

Opera:
18.400->20.136->19.680->19.224->20.568->20.428->19.440
19.180->19.444->19.360->19.648->19.116->19.372->19.276
19.228

FF:
21.116->21.700->22.172->22.488->23.060->23.484->23.972
24.192->24.656->25.156->25.852->26.068->26.600->26.956
27.292->27.892

As you can see, FF is the only browser where memory usage is consistently increasing after each refresh which indicates a memory leak. IE and Opera rather fluctuate but are not increasing memory usage.

Fixing this problem would be a good starting point in my opinion. Not too difficult to reproduce.

Posted by: Ignace at February 18, 2006 2:16 PM

This back-cache is not the only reason for the enormous memory consumption of Fx. I set the value from 8 to 1 when I read this article and there was no real advancement if any. After about 4h of being opened Fx now uses 120MB (RAM+Swap) with one tab opened. Also this increases all the time, which shouldn't be the case if the memory was mostly used for caching, as after some time the cache would be filled and not grow anymore.

It's just like this: Fx has a problem with memory management. No browser should need as much mem as applications like Photoshop, though Fx does. And it often does need even more. So there's something wrong.

I'm still using it, because the extension system makes this browser extremely powerful. You can by no means call it ressource-friendly though.

Posted by: Sturensohn at February 18, 2006 4:22 PM

It seems to me that this problem does not necessarily lie in Firefox. I use Firefox on Linux and have never, and I mean Never, encountered this issue, I use Firefox on Windows, and the problem is painfully obvious. Granted it may be an issue between the two versions, it just strikes me as odd that this 'leak' only seems to occur on Windows. As for all the people shouting about Opera, I won't deny Opera is good, but I never got on with it as well as I do firefox, although I did have fun fiddling about with the voice recognition :D
I don't know how many of you are programmers, or have the time, but if it bugs you that much why not take a look at the source code and see if you can fix this issue? It will do a lot more good than moaning about it.

Oh and I should add I don't buy this feature rubbish at all, this was a problem long before 1.5.

Posted by: Shiftyben at February 18, 2006 5:11 PM

I have to agree with other. I don't agree with this finding.

I had firefox using 1GB worth of memory. Even after closing all the tabs and other window, with only 1 window left, it continue to use 1GB memory.

To me closing tab should flush out all the cache that was related to that tab.

Posted by: applyum at February 19, 2006 12:04 AM

OK theres something odd going on, my message has come up posted under a different name, and someone elses posting has come up under my name

Posted by: Shiftyben at February 19, 2006 3:36 AM

and its just done it again

Posted by: Shiftyben at February 19, 2006 3:36 AM

It's a huge C/C++ program folks, so it will have leaks ;-).

The devs should consider plugging in the Boehm GC: http://www.hpl.hp.com/personal/Hans_Boehm/gc/ (not that it will fix the "leaks" where data is still referenced unnecessarily...)

Personally, I haven't had any memory hogging problems since a few months ago (must have been 1.0.2 or something like that), but I *never* use tabs.

As for the Opera cheerleaders here: fine, go use Opera if you like it better - but be aware that a lot of its apparent speed is due to cheating in the default cache settings (last time I looked the default was to ignore HTTP headers and cache documents and images for 5 hours, which caused problems with many sites).

Posted by: mjy at February 19, 2006 7:25 AM

I've only got 128 MB RAM, and whereas I could surf for hours with tons of plugins and up to 15 tabs with 1.0-1.06, now I'm lucky if Firefox doesn't lock up, slow my entire computer to a crawl, or crash within 10-15 minutes, even with only 1-3 tabs open and a fresh, plugin-free install.

The problem I've observed is that Firefox seems to have problems interfacing with Java, as if I'm unfortunate enough to stumble onto a site with an active applet within 5-10 minutes of browsing elsewhere, I'll be extremely lucky if Firefox doesn't crash. (Yes, I have the newest version of Java.) And Java-based games seem to throw Firefox into a RAM-gobbling frenzy! If I go directly to a Java-based game site and open no other tabs, Firefox starts to lag within 8 minutes and is practically useless within 20. I never had this problem with any of the 1.0+ releases, so it's obviously a 1.5-specific problem.

I've been using Firefox for three years now, and have been very happy with browser performance up to the 1.5 release. It's irritating how Mozilla keeps brushing off the same repeated complaints from so many, making lame excuses or blaming the users instead of actively fixing the problem. Instead, Mozilla is pulling a Microsoft and working on 2.0 rather than figuring out what went so dreadfully wrong with 1.5 and trying to correct an obvious error. It was this exact same type of indifference that caused most of us to switch from IE to Firebird/Firefox in the first place, and Mozilla would do well to keep that fact in mind.

Posted by: sca at February 19, 2006 8:11 AM

Ha! A feature not a bug..... now youre DEFINITELY sounding like the Microsoft people you all hate.

Posted by: mike at February 19, 2006 9:19 AM

mjy, there is no such thing as cheating. You have simply forgotten that even Firefox caches pages.

Posted by: xertnevnI at February 19, 2006 5:48 PM

xertnevnI: But you have conveniently disregarded what he said in his last sentence.

But I disagree that every huge C++ program will leak memory, have you seen Opera doing so?

Posted by: trenzterra at February 19, 2006 5:54 PM

It is up to a program to do what it wants in order to load faster, like having more connections etc. It is a rather level playing field.

Posted by: xertnevnI at February 19, 2006 5:55 PM

Yeah, if it causes problems with several webpages, then it's not a good solution.

Posted by: trenzterra at February 19, 2006 5:56 PM

You might have this sentence slipping out of your mind, but please bear in mind I said that "it is up to a progam to do whatever it wants".

Posted by: xertnevnI at February 19, 2006 5:56 PM

IE6 = 137MB (One window open 3 days)
FF 1.5.0.1 = 52MB (six tabs open 3 days)

I think that speaks for itself.

Posted by: ThePriest at February 19, 2006 10:50 PM

================================
Hope feedback from a programmer will help.

The performance issue comes from the Firefox
'Download Manager'.

When the problem happens, it does not matter
if I reboot the PC because the 'Download Manager'
list is still there (my settings is 'manually'
clean it).

It's obvious that it's the 'Download Manager'
because if I clean the 'Download Manager'
history then Firefox is working fine again.

The problem is that it can take 30 minutes (on a
high-end PC) to clean its list... so it also
takes indecent 30 seconds to 1 minute to ADD an
item to the list (hence the slow user interface
when you browse the Internet).

I switched the 'Download Manager' setting to
'after each download' and I guess that it will
resolve the problem for me.

I didn't dig into the code but my guess is that
Firefox loads in RAM the 'Download Manager'
history list. This allocates a lot of RAM and
slows down everything (Firefox is then using
50% of my dual-CPU resources, that is, 100% of
one CPU).

I am not affiliated to any browser development
so you can take this entry as pure feedback.
================================

Posted by: anonymous at February 19, 2006 10:59 PM

Ok, I'm an FF addict and not sorry for it. I've tried all those prescriptions....unistall unnecessary extensions and only keep the basic essentials..Adblock, NoScript, Tab Mix Plus, Google Safe Browsing..in total 12. Including Forecastfox i.e. Try open my Home tabs (8), then close to only four. FF is using roughly 3~30% CPU (512MB RAM). Try open Yahoo!, hell breaks loose. This even with havig edited the browser.sessionhistory....to 3! It was worse when I ran WindowsOnecare Beta and I uninstalled it. Still today I have had to restart FF six times in the last half an hour. Now I have changed the cache at about:cache to 20MB since I noticed Opera has set its to 20MB. At least I have bought myself some time. In the last 30mins I have had no crash. Honestly, the guys at FF have done a splendid job, albeit for free. However, there is a real issue about memory and this with the 1.5.0.1. I Love FF and am not about to give up my convenience, I run IE 7 Beta but I can't open all my home tabs in one swoop, which I do with a mouse click in FF. Admittedly I'm unschooled in this software writing stuff but I follow any advice keenly. Let us help our favourable browser by solving this problem, it's the best thing that happened to me on the net apart from Google desktop, of course. I have the three, IE 7, Opera and FF. Notwithstanding the previous crashes, I'm helplessly hooked to FF, and not without reason!

Posted by: Matelong at February 20, 2006 4:56 AM

I've been using FF 1.5 since the day it was released, since the day it was released it's system resource utilization increased by an order of magnitude. I've been a huge proponent of FF among my the users that I've been supporting and I've loved the app myself for quite some time but it's beginning to get ridiculous. I'm running a box with an Athlon 64 4000+ at 2.4Ghz and 2 GBs of RAM and my machine spikes to 100% CPU utilization when I simply close a window in FF. I did adjust my browser's page caching which brought my physical memory use to 250MBs from more than 300MBs, though my page file use is still at more than 250MBs. Like the poster above me I've been hooked on FF for years at this point and the reason has always been that page loading has been faster, rendering more smooth, but above all else FF was not a CPU and Memory hog like IE is. Given my recent experiences and the fact that 1.5 is this much noticibly worse than 1.05 I'm beginning to rethink the reasons that I switched in the first place. All that being said I am still willing to deal with this, for a while, and will never go back to IE.

Posted by: Josh Gerner at February 20, 2006 7:17 AM

Masz świetne program
Unikaj błęd�w !!!!
Zostaw komenta na http://wladca-pierscieni-fl.blog.onet.pl

Posted by: filip at February 20, 2006 7:47 AM

Even eliminating the cache altogether doesn't do any good. *shakes head*

Posted by: anonymous at February 20, 2006 10:26 AM

anonymous (5 posts up) wrote:

It's obvious that it's the 'Download Manager'
because if I clean the 'Download Manager'
history then Firefox is working fine again.

The download manager is part of the problem. The download manager's resource usage doesn't scale properly. It shouldn't matter if there's 5 entries in it or 50: there should be no significant effect on browser performance. Yet there is. Even though it's just a small amount of metadata, keeping a large list in there slows switching tabs, display of the File Save dialog, etc.

But even if you clean it out regularly, you still have memory and performance problems after loading and closing several tabs of pages with large images.

Additionally, the File Save dialog itself doesn't scale properly. When you browse to a folder that already has lots of files in it, expect it to take a long time to display and eventually allow you to click the save button. I thought that was a Windows problem that affected all applications using the File Save common dialog, but Opera saves in the same folders just fine, without the performance hit.

Bottom line: there are several different memory/performance issues, but I consider the most serious one to be whichever it is that causes out of control memory and pagefile usage on the order of 1-2 GB in worst cases.

Posted by: benthere at February 20, 2006 12:06 PM

A million posts up in this overstretched thread, advised setting Ben's parm to 3. Ever simce, whilst having 74 extensions, generally 5 tabs open and Olympics live stream tv running in 1 from across Europe in a IE 7 frame of IE TAB 1.08, it sits between 134 and 140mb (actually now at 121).... no uncontrolled memory growth after many hours open. Whilst 140 is still a lot, it is miles better than the previous 310mb record AND AGAIN, my browsing speed has substantially improved!!!!!! My 2 cents, lots of ill extensions....dumped a few suspects.

Posted by: sekerob at February 20, 2006 2:35 PM

As mentioned in a previous post, FreeRam XP Pro is an excellent temporary solution for the memory problem. I have it set to automatically release RAM every 30 minutes amd have checked the global memory compression in the settings. That way memory is compressed at the same time the AutoFree kicks in. It works very well! Furthermore, it is a free program!

Hopefully, Firefox will do something about memory usage.

Posted by: WBDUTCH at February 20, 2006 2:49 PM

I AM GOING BACK TO MICROSOFT

Posted by: Michel at February 21, 2006 10:14 AM

There are three kinds of browser caches:

1. Temporary Internet Files / Disk cache. This stores all the HTML, JS, GIF, CSS, JPG, PNG, etc. files on your disk so that the browser doesn't have to retrieve them over the network again, because the network is usually slower than the disk.

2. Memory cache. This stores recent HTML, JS, GIF, CSS, JPG, etc. files in memory so that if you click on the back button, the browser won't have to load it from the disk again, because the disk is slower than memory.

3. Back/forward cache. This stores the rendered page in memory, because parsing the HTML, decoding the images, and laying everything out according to CSS is slower than pulling the results out of memory.

#1 and #2 are common to most browsers. #3, or something similar, has been in Opera for a while, and is new to Firefox 1.5, and that's what Ben is talking about in this post.

Posted by: Kelson at February 21, 2006 12:14 PM

I was really surprised to see an article as dismissive as this from somebody involved directly with the development of Firefox.

Your users are complaining. It doesn't matter if it's a bug or a feature, the people who have come to love your software are getting pissed and don't deserve to have their opinions discounted.

I like tabs, but don't use them anywhere near as heavily as some posters here. I generally top out at 4 tabs and close them without going too far. I've watched the memory usage without using tabs on my Win XP box and it sucks. There is no excuse for having firefox take up 150 MB of RAM after visiting less than 10 pages in a single freaking tab.

On all my work machines, I have stuck to 1.0.7.
On my home machine, I'm going back to 1.0.7.

Once the problem is really fixed (no, 1.5.0.1 doesn't fix it at all) I will step up. If it doesn't get better, I will be forced to consider alternative browsers, something I thought I'd never do again.

Please, listen to your users. We're not actually that stupid. If you fix the problem (or make it easy to disable whatever "feature" is causing this) we will shut up and go back to surfing for pr0n.

Posted by: Richard Bone at February 21, 2006 8:52 PM

Hi,

I have the impression that the issues aren't so much a memory "leak" as a memory hoarde (sp?).

I open lots of tabs, and when I have lots of them open, Firefox's memory usage goes up. When I close a bunch of tabs, I'd like that memory usage to go down, but it doesn't appear to.

Is there some kind of memory pooling that keep allocated memory in this way, rather than freeing it up under certain conditions?

Cheers,
Dave.

Posted by: Dave Neary at February 22, 2006 12:32 AM

I really think the Problem is ADBLOCK!! After uninstalling it and only running with noia theme, forcecast- and fasterfox the memory usage never goes up over about 75 megs

Someone really should make some test with the extensions! If there is a hole im firefox itself and can be only profed by doing a clean installation without any extensions.

Posted by: Mathias at February 22, 2006 1:15 AM

I've been a long time Firefox user, since the Phoenix days when it was first broken off from Mozilla. Unfortunately the latest version of Firefox has not been a good experience for me, and I have been forced to look at other browsers. In my mind, the best browser currently is Opera. It has almost everything I need, mouse gestures, tabs, responsive interface, cross platform and skins (but no adblock :/ )

I will keep trying new versions of Firefox as they become available, but for now, Opera is the only choice.

Posted by: drleper at February 22, 2006 1:19 AM

After a few days checking email and web browsing with several windows open, but with most images disabled, no javascript, plugins or extensions, and only a few tabs, Seamonkey is using 1.5GB on Windows XP with 1GB of RAM. That's just ridiculous.

Mozilla 1.7 rarely got much above 200MB, and I thought that was a lot. I'm now seeing the "slow swap" problem again that i thought had gone away when this computer was upgraded. I don't want to use config.trim_on_minimize as I'd quite like other applications to get a chance at some RAM too.

Posted by: Roger at February 22, 2006 1:42 AM

I am a long time user. The nth comment is that this is getting worse the more you try to look like IE. If we wanted this headache we would have stayed with IE. I do not want this to sound bad it is just the way it is. Don't give people verbiage, give them the alternative they want. Even with a page cache some sites are better off being re-displayed as they are constantly changing. Memory is cheap but that does not mean because of bad programming decisions that we need to keep adding more. If everyone wanted the Microsoft way - no one would be down loading your product.

Posted by: Mech1 at February 22, 2006 8:52 AM

I'm thinking there is a memory problem. I'm going to disable adblock to see what that does. All in all FF has treated me well. Great product and thanks to all involved.

As soon as all the Opera rats jump ship the volume of FF downloads/users/word-of-mouth will decline and thus the FF people will get to the crux of the memory issue.

What other motivation can there be for a company that offers their product for free?

They certainly aren't motivated by the grattitude displayed by the comments here!

Posted by: vince at February 22, 2006 9:44 AM

I'm sorry to see my earlier post (some function Ben invoked to stop flame posts or something). It had confirmation on the functioning of a line to add to about:config, plus the setting for the memory cash. Combined with Minizime to Tray extension, now running 10 tabs, multiple page browses up and down, 1 of them a life tv stream in a IE Tab frame. Minimized FFX goes down to between 21-38mb, whilst streaming continues and maximised sits at between 60 and 112mb. I'm happy with this improvement.

Posted by: sekerob at February 22, 2006 5:00 PM

Is FF perfect? No. Is it horrible? Certainly not.

Am I glad I have something besides Internet Exploder to use on Windows? Hell yeah! :-)

If you are seeing repeatable problems with FF, then file a bug report. Maybe donate to the project too?

Opera is a good browser, and it's better than FF in some ways. However, I find FF is better for daily general-purpose browsing.

I've seen FF do some odd things, but I haven't seen anything as bad as some of the people here are saying. :-)

It's pretty amazing that FF is so good, is free, and beats IE many times over. It's also amazing that a huge company like MS with their masses of development peons can't compete with FF. Oh, and FF also runs on many more platforms that IE. MS can't even cope with 2 platforms.

I also wonder how many of the people complaining about problems with FF are using Windows? Could this be contributing to the problem? Does FF run better on other platforms besides Windows? (I'd say it's about even, but I was wondering what other people have found.)

Posted by: Stuart at February 22, 2006 5:48 PM

I didn't have any real problems until a week or so ago when I had to install XP SP2 because of a Microsoft partner software update; but since then, I've had many of the memory leak and slowness issues. I have done some tweaking, and it has helped, but to answer the question about whether it is a Microsoft related issue, I'd say at least XP SP2 related. My Linux boxes don't seem to have any issues, at the moment.

James

Posted by: James Grant at February 22, 2006 6:42 PM

> Does FF run better on other platforms besides Windows?

I find it's worse on Linux. It leaks memory itself and causes X to leak memory, and everything gets slower and slower until FF crashes (again no extensions, plugins or javascript). I recently switched from Mozilla 1.7 to FF 1.0 in the hope FF might be better, but it's not made any difference. It is better than NS 4 though, which used to crash within minutes of enabling javascript.

I wonder if the people who haven't seen any problems always restart their computer every day? I leave Windows running for weeks at a time and Linux for months.

I appreciate everything the Mozilla team has done, but it's not perfect and there is always be room for improvement.

Posted by: Roger Lynn at February 23, 2006 1:04 AM

I realize that you're talking about the fastback cache here. But I don't think that's the major issue. I think the general memory cache is the issue. In fact, I just went to about:cache, and I've got some pretty good evidence that there's a problem:

Maximum storage size: 31744 KiB
Storage in use: 49465 KiB

I have 1 GB physical RAM, Windows XP, SP2. Firefox is currently taking up 140 MB. I currently have 18 tabs open in one window. I frequently get to 50 or more tabs open at a time, and probably 100-200 tabs opened and closed in a couple days-long session. Memory usage can easily get into the 400 MB range.

The even bigger issue, is when I close a few dozen tabs, and I don't get any memory back. (I haven't checked if it's memory cache or something else. I just re-discovered about:cache.) I've not seen any good reason given for why I don't get memory back when I close a tab. I could understand 400 MB while I have 100 tabs open, but when I close 99 of them, there's no good reason for it.

Posted by: Craig Buchek at February 23, 2006 1:29 PM

I set browser.sessionhistory.max_total_viewers at 0, and still FF 1.5.0.1 uses a lot of memory. I have Tablet PC with Windows XP Pro, 1GB RAM, and according to Task Manager FF uses 188MB of RAM. What's going on?

Posted by: Robert at February 23, 2006 5:07 PM

I just want to mention I changed the browser.sessionhistory.max_total_viewers value from -1 to 0 and noticed the difference immediately. Firefox uses much less memory and even goes much faster--This should certainly be the default setting in future releases.

Posted by: David at February 23, 2006 11:38 PM

I am a long-time web developer (amongst other things), and the past 6 months I have been working on two web applications for clients. Both clients insisted on Firefox support (one even insisted on Safari support).

During my time working on these projects, I have noticed that there are significant memory issues with Firefox, and I do not beleive it is just due to page caching. All browsers implement page caching, including Opera and IE. With both of those browsers, I have little problem with memory usage (IE never uses more than 50 megs when I test).

I use FireFox 1.1 and 1.5 in plain-vanilla mode. No extensions, rarely more than two tabs open. I do use the back button, but I guess I rarely go farther back than 4 pages. I usually leave browser windows open for days at a time, just refreshing pages after I make a change. Opera and IE usually remain quite stable in terms of memory usage during extensive testing, but Firefox does have a continual increase in the amount of memory used.

I have 1.5 gigs of ram in my development boxes, so exessive memory usage isn't exactly a "problem", but it is concerning to see the browser sucking up 800 megs of memory after a day or so of testing. I've configured windows precaching for FireFox through my shortcuts (so it loads in a fraction of a second on subsequent opens, rather than 45 seconds or so), so even exiting FireFox and restarting it doesn't completely aleviate that excess memory usage.

If there is some kind of extended page caching in FireFox, which has the goal of improving performance when traveling through page history, I think a couple simple memory-saving solutions should be considered.

1) The most obvious solution is to time each cached page, and fully unload timed out data when the timeout is hit. If you store 8 pages worth of history, but the user hasn't hit some or all of those pages in several minutes, the memory being used for those cached pages should be freed.

2) Storing raw data in a cache may not be the best way. Some kind of lightweight compression technology could be utilized to shrink the memory usage of cached pages after a short timeout. Decompressing a lightly compressed chunk of memory is usually still quite a bit faster than loading from disk, and it should be possible to minimize the impact to memory usage while decompressing.

3) The history cache should be adaptive in multiple criteria. Rather than just hard-coding a specific cache size for all systems, the cache should detect the users free memory amount, and adjust page caching per-tab on a realtime basis as tabs are opened and closed. Taking this a step further, some simple tracking algorithm could be used to allow the browser to "learn" how its user browses. Its quite possible that some people will need the history cache less than others, some not at all. Improving the functionality of Firefox over time as someone uses it could go a long way to making it a faster, more stable browser for each individual user.

I don't know how possible such improvements could be with FireFox's current codebase. I have attempted to fix some bugs in the past, but FireFox is a fairly immense project, and trying to learn enough to fix a simple bug means learning half the code first. It may not be possible to add an intelligent adaptive cache, but if so, I do think it would help.

Posted by: Jon Rista at February 24, 2006 11:13 AM

Mathias -

Good discovery! Darin Fisher ran some tests with Adblock and found that it was leaking pretty much every page you visit. I've never seen this myself because I don't use Adblock - and I imagine a lot of other developers don't either. My recommendation is for people concerned about this to try running with Adblock disabled and see if things improve.

Posted by: Ben at February 24, 2006 5:06 PM

naviging performance feature was decided by navition study. I'd like to see navigation study

"navigating (studies show that 39% of all page navigations are renavigations to pages visited

Posted by: dobiho at February 25, 2006 6:50 AM

I found the cause of the horrendous leak in my case. It was that I always run Windows using a Limited User account, never administrator. On a hunch, I tried running two instances of FF at once, one as administrator, and one as my limited user account, and doing the same things on both that trigger the memory bloat (refreshing large animated GIFs works very well).

Guess what? The FF running with Administrator rights did not bloat, the one running with Limited User rights bloated up like a zeppelin.

Posted by: Gigabit at February 25, 2006 7:09 PM

I should correct my last post. I didn't run both instances at the same time, that turns out to be impossible. But I did run the same tests on FF under the same user account both times, only difference being whether that account was an Administrator account, or a Limited User account.

Under Limited User: FF doesn't ever seem to release memory, and bloats to the point of making windows sound the low memory alarm and resize the paging file.

Under same user account, but promoted to the Administrator group: FF runs fine, and I can't make it bloat up even if I try.

Posted by: Gigabit at February 25, 2006 7:51 PM

Depending on your platform, I think there's quite a few things that FF is having pinned on it here that is completely unfair. I cannot speak to running FF under Linux.. I use Linux for server purposes only. Windows, however, brings up several questions in my mind. I sit down in front of so many different Windows 2000 and XP computers every day.. they all generally have the same crap wrong with them. How much maintenence do you do to your machine? How often do you clean out the completely unneccessary crap that builds up in your c:\docs&settings;\username profile? or C:\windows\temp? Downloaded Program Files? Prefetch non-sense? Checked the size of your registry lately? Ever tried setting your PC up exactly the way you want it and making a ghost image? If something goes wrong that system restore (Which I think should be permanently off anyway) can't solve, Move your data off, restore from the ghost image, update what you have to, and viola.. no more bullshit. I can do it in 2 hours on my laptop. That's it. Oh, and remember Defrag? Yeah, it still works. Periodically deleteing c:\windows\prefetch helps. Getting rid of tooltray apps and run key programs you never needed helps. The browser is doing it's best. It's a ***volunteer*** effort. I bet if you and 15 of your best friends sat down with all the knowledge you could pool together you wouldn't come close to what firefox was accomplished. Hell, I won't bet you - I know that's true. Otherwise, you would've already done it.

In time, it will get better.. But, geez.. Start with the basics. I have seen the same odd memory usages in FF sessions as well. But not every time.. not with every websites.. not even with the same ones day in, day out.. not with every extension loaded.. all running 1.5. In the last few months I've caught FF using more memory than I would've liked two or three times. That's it. Every time, I had loaded a java app. of some kind. Hmmm... But I have also notice the conditions change as I change conditions in XP that have nothing to do with FF.. Troubleshooting is about starting from the ground up - the foundation UP, and eliminating facts which have no effect and/or do not change the "complaint" or "condition." Quit blaming the browser and start blaming the neglect of your system, your inability to understand spyware/malware to more technical levels, your completely misdirected anger because (wah) you have to restart a program.

Time and time again through this ridiculously long blog, I saw two things:

"I hate it and its memory management.. it sucks! fix it! Oh, btw.. I love it, too. Thanks for a great browser."

and...

"GOD, what is WRONG with you developers? Do you think we care if you have lives? FIX it or I'LL GIVE UP ON FF FOR GOOD! Well, not yet.. cuz Opera still doesn't do everything I want yet, and IE 7 just looks f'ing scary.. but, god dammit, FIX IT! NOW!!!"

Both arguements are... mute at best. None offer any help, aid, or worthy information other than "yes, we can add you to the list of people upset about memory management." Try going back 10 years.. or 15 years.. and gripe at me about memory management. It was a hell of a lot more annoying when you had to manage it yourself! You'd think most of the responders to this post (I said most) were born in 1985 or later!

This post started out as an awknowledgement from Ben that there was a problem, and in the grand scheme of hundreds and thousands of users, they wanted to offer a possible (keyword being possible) solution/workaround. Maybe the possible solution didn't pan out the way YOU wanted - can you really assume it tells them nothing? -sigh- It is a shame he had a bad choice of words in the beginning of this blog which caused such great misunderstanding, but atleast he corrected himself. Half of you sound like you just want to kick his ass for even bringing it up!

So much misdirected anger... If you don't have any TECHNICALLY beneficial information to offer, how about being patient, or testing your own environment a bit further. Who knows, you just might solve your own problem.. with a video driver update, disabling services you don't need since you're not on a MS domain environment, defragging yer fricken messy drive.. it's just a fricken PC, folks. Go walk the dog and dream of better days.

(For the record, the system I use while lounging in my living room is a P3 500mhz, 256mb of ram, 40gig HD, 802.11g.. I tend to match the disk cache config in FF to the amount of RAM I have.. one theme, four extensions - tabrowser preferences, ietab, adblock (well configured), and talkback. Usually have 4 to 12 tabs open. Typically stick with one session. I've never had FF crash, nor have I ever had FF or Windows tell me it was running low on virtual memory or system resources. You do the math. I usually have Outlook 2003 open as well, two sessions of IE, remote desktop or two, and am listening to a shoutcast stream in Winamp5. If it's as bad as you all say it is.. that should not be possible. My system may not be as flashy quick as your P4 3.8hz, 2gig ram, 2 250GB 7200RPM SATA drives - but I've never once seen FF take up more than 65 to 75 meg of RAM. Just restart it and be patient - or teach yourself how to code, roll your sleeves up, and get started. I guarantee you, you'll be too busy to bitch.)

Posted by: JBL at February 26, 2006 9:23 AM

I think there is problem with yahoo mail and firefox 1.5 compatibility with regards to browser.sessionhistory.max_total_viewers.

Posted by: Chris at February 26, 2006 4:44 PM

Feature or not, fact is on a AMD64 box with 1GB RAM, surfing for porn becomes unbearable. Within 20 minutes, Firefox consumes +800MB RAM.

Posted by: Quake3Boy at February 27, 2006 6:36 PM

reading the 3 page contribution of JBL I see a few contradiction interminee in what he's writing, whilst he's implying the users really all should be hi-ly qualified sys-admins.....meantime as i monitor FFX and tweaked it according to Ben's tip and a few more follow ups to that, i'm at awesum 148mb after having it 2 days open, hi-res streaming, hi res this that and a dozen tabs and chats and the whatnot...less than half of what the record 310mb mem size was previously with a lot less effort....wont say more of the part that need solid improvement...we all agree i think....76 extension at moment :>]

Posted by: sekerob at February 28, 2006 1:42 PM

how do i change this setting ? my firefox is about 150mb as soon as i open 4 tabs

Posted by: ouendan at March 3, 2006 12:42 PM

Dudes, there is a memory leak in FireFox. Rather than attempting to shift the blame to cache sizes or plug-ins, someone needs to find the leak. It's serious. FF was using nearly 700MB of memory, bringing my total Windows memory use to over 2GB. Since I have 2GB of real memory, my system then became really sluggish as things started swapping to virtual memory. I do not use Adblock, so don't go there.

As it happens, I had just switched to using FF a few weeks ago. So I have a workaround to the FF memory leak: going back to IE6 for now. Sorry; it's too annoying. And I'm not a tabbed browser fan, so I won't horribly miss FF. I prefer the keyboard over the mouse, and ALT+TAB switches me between IE (and other Windows apps) very, very rapidly. I haven't found the shortcut key sequence to switch between tabs, and even if there is one, I'd have to remember in my mind whether I want the key stroke to switch back to my last viewed tab or my last viewed Window. By the time I've figured that out, my fingers have already hit ALT+TAB.

Posted by: RobO at March 4, 2006 5:46 AM

"first of all, opera and firefox are both made by the same company."

"You are very confused."

*******

You're confused too. They were made with different brain.

Posted by: Clazirus at March 6, 2006 1:07 AM

""first of all, opera and firefox are both made by the same company."

"You are very confused."

*******

You're confused too. They were made with different brain."

Now im confused >_

Posted by: rederanged at March 7, 2006 4:40 AM

Hmm...

my last comment is a bit funky... someone should look at that when they delete that spam.

wonder what happens when i go >_

Posted by: rederanged at March 7, 2006 4:46 AM

Like someone said above, I have been using FF 1.0 on my computer with a meager 256 MB RAM, and I never had to close FF when it comes close to halting the whole computer. Since when I moved to 1.5, this has become such a pain, and what's worse is that even if I *CLOSE* Firefox, firefox.exe (yes, I use Windows) continues to run and I have to manually "End Task" it. This is so bugging! But I love Firefox! I don't know what to do!

Posted by: Devdive at March 7, 2006 1:32 PM

Devdive - I agree totally. My older laptop only has 256 meg and is only used for some browsing. I never had a problem with Firefox until 1.5. Now I level a couple of FF windows open and a bit later discover my system almost totally hung, and firefox.exe using 150MB of my ram.

IF I can manage to close the FF windows, the firefox.exe is often still in the tasklist and still increasing its memory usage! I have to kill it with the task manager.

Carolyn

Posted by: Carolyn at March 7, 2006 3:13 PM

For the word "level" above, read "leave"

Carolyn

Posted by: Carolyn at March 7, 2006 3:14 PM

i'm not sold on the "this isn't a bug" point... this morning i did some surfing, perhaps ten tabs open, then closed all but one and left the browser alone for 2+ hours. i happen to glance at the mem usage reported by task manager after this time passed, and it said over 300MB used! so tell me why after i've closed all tabs but one, and the tab i left open had NO history (had never left the initial loaded page), does Fx insist on keeping 300+MB ram hostage? there's no page history for me to reload!

unless task manager reports incorrectly?

Posted by: jeff at March 8, 2006 9:46 AM

Thing is, this problem has been around LONGER than firefox, and I've seen it from 0.9 right through to 1.5, and on every OTHER GECKO BASED BROWSER ON EVERY OS I'VE TRIED!!!

In fact, almost two years ago now (at least a year and a half), I added my voice to a bugzilla entry on the very same error, with explicit instructions on how to recreate it... and the best they could come up with for a response was to leave it unconfirmed and try to take me to task for using the term 'crash' instead of 'hung', a distinction I've not heard in what is rapidly approaching three decades of computing.

The support channels like bugzilla are populated with arrogant asses who seem to prefer insulting people to addressing their issues, and the developers seem to have a "ostrich with it's head in the sand" complex over things like this gecko related memory problem, which HAS BEEN AROUND SINCE BEFORE FIREFOX WAS A TWINKLE IN A OSS FANBOYS EYE. I'm sorry, but over a year and five sub-release versions and it STILL chews up half the system RAM and >90% cpu after a mere fifteen minutes use (at least, the way I browse) with the only page open being GOOGLE, without any REAL attention to the problem... it causes a lack of faith.

I woulnd't even KNOW how buggy it still is if it weren't for the fact I'm a web coder, and have to test for compatability DAILY with most every browser I can lay my hands on, be it IE, Safari, Firefox, Opera, what have you. It actually pisses me off to even HAVE gecko based browsers installed after the BULLSHIT I went through on bugzilla.

Now that Opera is free, there is NO good reason to use something as buggy, unpolished and ... unfinished as Firefox... Hell, the Opera 9 beta's have been more reliable than the Firefox STABLE releases.

Posted by: deathshadow at March 9, 2006 8:56 PM

As I write this I have almost given up on something I like most. The integration of the Blue Frog anti spam extension into FF 1.5 makes my spam reporting effortless. However, I almost can't work with Yahoo! Mail in FF anymore. The page crushes and I have to do the manual reporting of spam. Anybody with helpful info out there? I'm desperate, I need my FF to work with Y!Mail, badly. Additionally, the Yahoo! page cannot display properly. Any plug-in to help this?

Posted by: Matelong at March 10, 2006 7:22 PM

Well I found that setting mentioned for the fastback cache and changed it to zero. I figure with a 3mb brouadband connection how long could it take to reload a page???
Sure enough the Firefox memory leak has gone down by half!! I don't see any difference yet in page load time. I went back and forth between 5-6 pages with graphic and audio content and didn't notice any difference.
Change that setting guys!!!!!!!!
Oh and go to www.stickninjas.com, they're cool :)

Posted by: guy at March 15, 2006 3:11 AM

Well when I start FF and have several tabs open after surfing for say two hours the memory use is at about 50Megs. If I leave all as is and go to sleep, the next morning the memory use is at 200Megs or more. This is not a "feature" it is a problem, great browser otherwise only inconvenience is it has to be shut down and restarted coupla times a day.

Posted by: LeslieC at March 16, 2006 6:01 AM

"whew, thank you for explaining this to all the idiots who've been calling this a memory leak issue."

Sounds like you didn't really have any clear answers yourself. Idiot.

Posted by: Philge at March 18, 2006 6:28 PM

I haven't tried leaving firefox open more than a day at a time, I usually close it (just habit, when im done, even if i will return, i close the one window i ever have open).

But for a little nonscientific test, with 4 tabs open, i had just barely under 50MB memory usage, not bad, i then went to my homepage (google.com/ig, all ajax), and followed a link from there, going through about 15 pages, then went back through them with the back button, not any real problem, and memory usage was at about 60MB. i then opened 3 ROWS of tabs (firefox was about 1000pixels wide) and when all was open, memory usage was at 180MB, after closing all but the original 4 tabs, firefox is using (right as i type this, and i haven't closed firefox since before i started this test)111,608 KB. I still think this is too high considering i closed most of the tabs. so all things considered, there is some kind of either "memory leak" OR "poor design" involved in the memory management of tabs within Firefox. (I say this because when i close all those tabs, my memory usage should drop back down close to 50MB)

ps. With all those tabs open, jumping around between them, and navigation within the tabs was still as snappy as ever, showing minor slowdown only once.

System Specs:
AMD Athlon64 3000+, 1GB DDR400, WinXP Pro SP2, Firefox 1.5.0.1

-incineratedDream

Posted by: incineratedDream at March 19, 2006 12:02 PM

bah! Feature or not, Firefox's excessive use of system resources has forced me to change browser. Disappointing, as other than this I was extremely happy with FF. Just tried Opera and boy am I glad I did. Somehow it manages to navigate backwards and forwards blisteringly fast without squeezing the life out of my system. Fix this "feature" or risk losing more users.

Posted by: HappySurfer at March 19, 2006 3:18 PM

Hi all.

I'm sorry to say, but something has happened to the FF codebase some around or after 1.2. These days (and this is on three totally different PCs: my dad's home computer, my home computer, and my work computer): I find myself rarely able to keep the thing running (under continuous use) for anything more than a couple of hours or so. I will typically have to shut it down *upwards* of 3 times a day if I'm doing a lot of browsing. Either the memory usage skyrockets or it sits there eating up 99% of my CPU for no apparent reason.

Don't get me wrong—I love the idea behind Firefox and the fact that its typically safer than IE. I used Mozilla when it came out, and had set FF as my default browser before any of the FF hype. I had the "Get FF now" sigs in my emails,... But I'm not anyone's fanboy and won't praise a product just because its free\open-source\not-MS, etc... This program is buggy (feature my ass! :( and extremely frustrating to use.

I hope the developers of FF take heed of these messages and try to work on stabilizing the codebase before adding anymore features. Perhaps they should even look into rewriting parts of the system from scratch, because it seems like there is something seriously wrong with the code under the hood.

-mike

Posted by: MikeC at March 31, 2006 12:22 PM

Great, I have to come after the fracking
porn. . .

Ben,

I've been reading through a lot of these posts, and all I see is a bunch of whiny people complaining about a FREE program written by people who AREN'T in it for the money.

If you're complaining because your page file usage skyrockets while you have 15 tabs open in each of your three nightly-built browser windows, then you need to GET A LIFE.

If all you're gonna do is bitch, then go use some other browser--like the one you have to pay for (Opera), or the one from Redmond that's full of security holes and hasn't been upgraded in years.

I want to say a big thank you to Ben, and to everyone at the Mozilla Foundation for all of their hard work and dedication, without which there'd be no Firefox for all you whiners to complain about. This program is free, created by what is (or was, anyway) a non-profit organization.

I can't thank the Mozilla Foundation enough for rescuing me from Internet Explorer, and I certainly know better than to bitch about something that was given to me for nothing.

Good work, Ben. Good work, Firefox team. Good work, Thunderbird team. Good work, Sunbird/Lightning team. Good work, Camino team. Good work to ALL of you.

Posted by: Rocky at April 10, 2006 4:45 AM

Firefox is currently using 200mb of RAM with 8 tabs open. I have 512 megs of RAM. I started getting alerts about low virtual freakin memory last night with it jumping up to 300mb.

If this is in fact a "feature", I really wish it would be removed. I think Firefox is getting way too heavy duty. I liked it when it was the speedy little web browser, now it's getting bloated like the Mozilla suite :(

Posted by: Frank at April 10, 2006 4:52 AM

Here you can find a way to increase the high mem usage of firefox by CHIP!

http://www.chip.de/bildergalerie/c1_bildergalerie_19407531.html

It works.
Now I opened 30 tabs and firefox uses only 42.540 K :D

Posted by: Hello from Turkey at April 14, 2006 7:14 AM

this may be a stupid question, but how do i see how much memory firefox is using? I look at the task manager and it only shows 24,000 kb. Id there an xp command that show more in depth usage? Thanks

Posted by: chad at April 15, 2006 11:26 AM

This is a ridiculous explanation for the memory use of Firefox. When I run Firefox it consumes increasing amounts of memory, depending on the time it has been running. Consumption of over 100 MB RAM is not unusual. How do 8 cached pages explain 100 MB of RAM use? It doesn't. I'm sorry, this just doesn't explain anything!

Posted by: Vuzman at April 26, 2006 5:22 AM

how bill gatesque of you to not call the memory issue a bug, but a feature.... How can there even be people thanking for this???... B0ll0cks

Posted by: Dixoo at May 4, 2006 6:10 AM

Use the opera browser Its the better than FIr

Posted by: domain name at May 19, 2006 3:29 AM

I keep seeing people saying, "Thanks for the explanation." Something tells me that half of those people would be content with the issue if the explanation was "It sucks up memory because we just wanted to see if we could get a few pages' worth of people pissing and moaning."

Maybe I'm a dunce, but I honestly fail to comprehend the idea of "unused RAM being wasted RAM." That's about like saying that unused closet space is wasted closet space. So sure, we'll just stuff everything we accumulate of 6 months into it, just so it's not "wasted." This *has* to be a joke. Know what you can do with unused closet space? Put stuff in it. But if you keep on putting stuff in it, eventually, there's not going to be any ROOM left to put stuff in it. At this point, it becomes neccessary to clean out the closet before anything else that you want in the closet can be put in it. This, however, requires more effort than simply NOT stuffing the closet full of things you don't need, and is really not very convenient. Quite the opposite.

Your RAM is quite like a closet. So tell me, do you honestly think it's smart to just keep filling our digital "closet" until we have to "clean it out?" Really. Assuming for even a moment that this is a significant cause (or even just a mentionable one) of Firefox's gluttonous memory management, if I were to take that phrase even remotely seriously, I do believe I'd be driven to tears. That's absolutely ridiculous, and if in fact it's true that this "feature" is a contributing factor to the drag, then I'd like to ask SOMEONE on the development team to kindly help me keep "my closet clean."

Posted by: Halcyon at May 23, 2006 1:21 AM

Another issue: Why are page saves so much slower in 1.5? Doing a save-as used to be instant. Now, it appears that instead of just saving what's already downloaded, it kicks in the download manager and re-downloads the page. The browser locks up until the download is done. Maybe it's worse for me because I'm on dialup, but it seems nonsensical to download a second time, much less make the browser freeze while doing it, and it's quite annoying when I've got ten tabs open and want to save them all.

Posted by: dennis at May 30, 2006 8:21 AM

hm, tons of comments already, but could the RAM usage be platform dependant? I only run Linux and with tons of tabs open Firefox uses about 60-70MB with 512MB RAM. I never had any problems with the memory usage...

Posted by: Anonymous at June 2, 2006 5:58 AM

I recommend to use Firefox, it is the surest browser and now with the actual version (1.5.0.4) is solved this memory leak.

I never had problems with Firefox on the other hand with IE I usually had
problems with Spyware and Dialers.

I the following link you can download the Firefox Browser, this version
included an orthographic corrector.

Download Firefox with orthographic corrector

Posted by: Download Firefox at June 8, 2006 9:43 AM

Hey all, i got the "msg", low virt mem, and being an ole schoooler. My dumb ass starts deleting progs..lol.
Then I realized I might wanna do some research.
Jee whiskers, I feel as old as IMUS sometimes....
There aint nothing wrong with this ole box :)
dave

Posted by: mr_icepik at June 9, 2006 2:37 AM

Firefox HAS a memory management problem / leak and if Mozilla is blind to this, then we might as well support Opera, which does not suffer from the same issues that FF does. Nice try guys, but right now, it's just not working as it should!

Posted by: framedsheep at June 11, 2006 3:34 AM

@Gigabit: It WAS happening the same with me (Memory leak: Administrator versus Limited Account issue). Try the following:

1.- Go to your Profiles dir and open prefs.js
2.- Find the entry user_pref("config.trim_on_minimize", true); and manually delete it
3.- Now, run Firefox and type about:config
4.- Right Click in the page and select New -> Boolean
5.- In the box that pops up enter config.trim_on_minimize. Press Enter.
6.- Now select True and then press Enter.
7.- Restart Firefox.

Now you have to just MINIMIZE Firefox to fix the memory leak everytime it occurs.

It worked for me :)

Posted by: aeon at June 21, 2006 4:57 PM

@Gigabit: It seems that the new version (or new versions?) does NOT recognize the instruction (user_pref("config.trim_on_minimize", true);) if it has been introduced previously...

Well, like I said, it's working now for me ;)

Posted by: aeon at June 21, 2006 5:06 PM

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