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Add Note Step 17

  • Here are two side X-rays of the A4 processor.

    • The dark dots along the inside of the processor are solder balls connecting the dies together. These are known as Ball Grid Arrays (or BGAs) in the industry.

  • These pictures are shot at two focal points across the width of the processor. They were quick shots, so we apologize if they're a little fuzzy.

  • The DRAM in the A4 is made by Samsung, so wirebonds are coming from both sides—unlike other DRAM modules Chipworks has seen from other manufacturers.

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Add Note Step 18

  • This is a die metal 8 layer.

  • Every iPhone processor that we have dissected has had a Samsung part number on the processor die. We have not found any Samsung markings on the A4 (outside of the DRAM), perhaps the clearest sign to date that Apple is in firm control of the semiconductor design.

  • We don't expect to find any markings from PA Semi, Apple's recent acquisition, but it's safe to assume they played a major role in designing this package.

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Add Note Step 19

  • This is the SDRAM inside the A4. Yes, that's a Samsung logo. No, that doesn't mean Samsung designed the A4—just the RAM.

  • Samsung's 1 Gb mobile DDR SDRAM (x2)

    • The part number on each die is K4X1G323PE.

    • Decoding this part number shows there is 2Gb of memory inside. This translates into ~128MB of memory per die, for 256 MB total.

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Add Note Step 20

  • So now that we've seen the inside, what can we conclude?

    • There's not much revolutionary here. In fact, the A4 is quite similar to the Samsung processor Apple uses in the iPhone.

    • It's clear from both hardware and software that this is a single core processor, so it must be the ARM Cortex A8, and NOT the rumored multicore A9.

    • It's quite challenging to identify block-level logic inside a processor, so to identify the GPU we're falling back to software: early benchmarks are showing similar 3D performance to the iPhone, so we're guessing that the iPad uses the same PowerVR SGX 535 GPU.

    • The iPad has 256 MB RAM, same as the iPhone.

    • The A4 sips power. In fact, power consumption is probably the reason Apple hasn't stepped up performance much from the iPhone. In order to get 10 hours of battery life, the entire iPad (including display) has to pull less than 2.5 Watts on average.

  • That's it for the A4. Let's take a look at some of the other chips inside the iPad.

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Add Note Step 21 — Inside the rest of the iPad

  • Capacitive touchscreen controller.

    • Broadcom BCM5974

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Add Note Step 22

  • Broadcom's I/O microcontroller with NVM (used for touchscreen)

    • Broadcom BCM5973KFBGH HS0951P11 952280 B1

    • Apple 343S0446

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Add Note Step 23

  • The Texas Instruments touchscreen line driver.

    • CD3240A 01D5AKT G1

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Add Note Step 24

  • Broadcom 802.11a/b/g/n WiFi + Bluetooth 2.1 + EDR and FM.

    • Broadcom BCM4329XKUBG CD1004 P21

Add NoteNotes: Step 19

Flag Reply by rab777hp Apr 5 @ 5:20 PM

Hey, you might want to let WSJ know about this, I read an article in which Kyle Wiens gave an interview about the A4 and I remember it clearly stating that samsung made/designed the A4. May want to correct them on that.

iFixit Staff

Flag Reply by Kyle Wiens Apr 5 @ 10:29 PM

The exact quote in the article is "The proximity of the chips suggests that Samsung also manufactured the A4 for Apple." I think that's a fair assessment. Hopefully we'll find out tomorrow for sure.

Flag Reply by com ctrl6 Apr 6 @ 2:14 PM

Manufacturing (fabricating) is different from designing. Samsung might have very well manufactured the chip for Apple, since Apple doesn't own any fabrication facilities. Apple designed the chip and Samsung fabricated it for them. Make sense to me.

Flag Reply by rab777hp Apr 6 @ 7:24 PM

Quote from Kyle Wiens:

The exact quote in the article is "The proximity of the chips suggests that Samsung also manufactured the A4 for Apple." I think that's a fair assessment. Hopefully we'll find out tomorrow for sure.

Ah, ok, I was misremembering the article then. Thanks for the clear up.

Flag Reply by mwhibben 1 week ago

Quote from Kyle Wiens:

The exact quote in the article is "The proximity of the chips suggests that Samsung also manufactured the A4 for Apple." I think that's a fair assessment. Hopefully we'll find out tomorrow for sure.

Any further information on the manufacturer of the SOC?

Flag Reply by Watt 5 days ago

"Decoding this part number shows there is 2Gb of memory inside. This translates into ~128MB of memory per die, for 256 MB total"

I'm sorry for being a noob, but I don't understand this sentence. If there is 2GB of memory inside how is there a total of 256MB?

iFixit Staff

Flag Reply by Chris Cline 5 days ago

Quote from Watt:

I'm sorry for being a noob, but I don't understand this sentence. If there is 2GB of memory inside how is there a total of 256MB?

GB is gigabyte, Gb (lower case b) is gigabit. 8 bits = 1 byte.

Flag Reply by Watt 5 days ago

Quote from Chris Cline:

GB is gigabyte, Gb (lower case b) is gigabit. 8 bits = 1 byte.

Thank you. That makes sense. I appreciate the info.

Flag Reply by Watt 5 days ago

Quote from Chris Cline:

GB is gigabyte, Gb (lower case b) is gigabit. 8 bits = 1 byte.

Thank you. That makes sense. I appreciate the info.

Flag Reply by luwoze 13 hours ago

Quote from Chris Cline:

GB is gigabyte, Gb (lower case b) is gigabit. 8 bits = 1 byte.

Flag Reply by luwoze 13 hours ago

The author was ambiguous - if your unit of measurement is in 'bits', it should be the same unit throughout the text (and it's equivalent in 'Bytes' given in parenthesizes).

Flag Reply by rab777hp 12 hours ago

Quote from luwoze:

The author was ambiguous - if your unit of measurement is in 'bits', it should be the same unit throughout the text (and it's equivalent in 'Bytes' given in parenthesizes).

Well know, because different things are measured in different units.