AMD Athlon 64 X2 Preview

AMD Athlon 64 X2 Preview

A look at what AMD's new dual core 4800+ processor is going to bring to your computing table. We directly compare and contrast it with Intel's dual core Pentium Extreme Edition 840 in our basic benchmarks and real world heavy duty multitasking.


Today AMD is allowing us to share a preview of their upcoming 939-pin dual core processor that will be officially named the "AMD Athlon 64 X2" series. The official launch will be in very early June.

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The CPU we have for you today carries a model number of "4800+" and is not directed at the gaming market as we are used to seeing in previews of the past.

Line in the Sand

As you can see from the slide below, the Athlon X2 series is squeezed in between the Gaming Segment and Mainstream Segment.

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The Athlon X2 is specifically built for a more involved computer user, one that heavily multitasks or uses their computer for digital content creation such as video editing. This is the same marketing strategy we saw Intel use at their dual core processor launch, but I think that AMD has done a better job at defining the segment with less confusing marketing. What you will find on the following pages though, is that AMD's Athlon 64 X2 fully blurs segment lines with its solid gaming performance. In fact, if you are a gamer that would truly like to multitask, this may the first time you have ever had that option.

Dual Core Differences

Below we see a flow chart for our AMD Athlon 64 X2, which is also extremely similar to the dual core Opteron, but with fewer HyperTransport bus connections.

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Where AMD differs a tremendous amount from Intel in the dual core department is that AMD did not just "glue" two of their high performance processors together. In fact, if you talk to Fred Weber, AMD CTO, he will tell you that AMD has been planning for dual core CPUs for a long time and the fact of the matter is that AMD's superior dual core design backs up that statement. AMD uses what they call Direct Connect architecture. Instead of two processor cores being saddled to one bus and run to a single memory controller as we see with Intel dual core technology, we have to remember that AMD Athlon 64 processors have the memory controller on the CPU die itself and therefore no “front side bus” is needed. So each CPU on our dual core X2 has a much quicker route to the memory controller as with current Athlon 64 processors. Also, each CPU core has its own 1MB of full speed L2 cache and the L1 caches are of course independent as well. So still the biggest benefit to the entire K8 core system is shining through in AMD's Athlon X2 line in the ways of HyperTransport and its extremely wide bus width when compared to Intel’s dual core 800MHz bus.

Below we see an image of the X2 core itself.

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Notice that you are seeing two identical K8 cores that are basically connected through a HyperTransport bus. That explanation is of course a bit oversimplified, but the payoff is in the performance as we will see on the coming pages.

AMD Dual Core Platform Advantages

The shining spot about AMD Athlon 64 X2 processors is a bright one that most of our readers are going to simply love.

For starters, the Athlon 64 X2 is already supported by nearly every 939-pin motherboard already on the market. We are told that most 939-pin motherboards will only need a simple BIOS flash to make the AMD Athlon 64 X2 compatible. We are currently running our Athlon 64 X2 on a production ASUS A8N-SLI motherboard with nothing more than a BETA bios. So many of us will see an upgrade to dual core with little more than the purchase of a processor.

If that were not enough, AMD has done some very slick things with Athlon 64 X2 power consumption, much as we have seen them do with their low power "mobile" processors. The power consumption is low enough for the dual core technology that no heatsink updates are needed, so most Athlon 64 thermal solutions currently on the market will fare just fine.

AMD Athlon 64 X2 Models & Specifications

Below we see what CPU-Z sees:

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Along with our usual CPU-Z screen shots, we have included a Task Manager Performance view with one instance of Prime95 running in order to load the CPU…or at least load half of the CPU. CPU-Z shows two physical processors as you would expect. In the task manager screenshot, you can see the two cores sharing the load of Prime95 at 50% utilization. Two instances of Prime95 would need to run to fully load our AMD Athlon 64 X2.

Below are the AMD Athlon 64 X2 processor line specifics snipped directly from AMD.

Frequency / Cache Sizes: 4800+ 2.4GHz w/ 1MB L2 cache-per-core (*)

Frequency / Cache Sizes: 4600+ 2.4GHz w/ 512KB L2 cache-per-core*

Frequency / Cache Sizes: 4400+ 2.2GHz w/ 1MB L2 cache-per-core*

Frequency / Cache Sizes: 4200+ 2.2GHz w/ 512KB L2 cache-per-core*

L1 Cache Sizes: Each core has its own 64K of L1 instruction and 64K of L1 data cache (256KB total L1 per processor)

CPU to Memory Controller: same as CPU core frequencies

Memory Controller: Shared integrated 128-bit wide memory controller

Types of Memory: PC1600, PC2100, PC2700 and PC3200 DDR memory

HyperTransport Links: 1

HyperTransport Spec: 2GHz (2x 1000MHz / DDR)

Effective data bandwidth: 14.4 GB/sec [8GB/sec x1 HyperTransport link + 6.4GB/sec memory bandwidth]

Packaging: 939-pin organic micro-PGA

Fab location: AMD's Fab 30 wafer fabrication facility in Dresden, Germany

Process Technology: 90nm (.09-micron) Silicon on Insulator (SOI)

Approximate Transistor count: 233.2 million

Approximate Die Size: 199mm2

Nominal Voltage: 1.35-1.40V

Max Thermal Power: 110 W

Max Ambient Case Temp: 65 degrees Celsius

Max Icc (processor current): 80A


AMD Athlon 64 X2 4800+ = $1,001 each

AMD Athlon 64 X2 4600+ = $803 each

AMD Athlon 64 X2 4400+ = $581 each

AMD Athlon 64 X2 4200+ = $537 each