Memory Test Configuration

When the article on AM2 processor performance was published a few days ago, the highest performance that could be reached with stability was DDR2-800 at 4-5-4 timings. A new BIOS will now allow the OCZ PC2-8000 reviewed in OCZ EL PC2-8000 XTC: Low Latency PLUS DDR2-1100 to run at 3-3-3 timings in AM2 prototype motherboards. This matches the highest performance achieved with this memory at DDR2-800 on the Intel 975x platform and allows a better comparison to fast DDR-400 memory on the AMD Socket 939 platform.

Pictures of the motherboards used for testing and/or photos of the AM2 processors tested might compromise our product sources, so there will be no pictures with this article. We can tell you that we now have several AM2 motherboards of very recent chipset updates along with several earlier boards that perform at a lower level. We are also testing our 4th spin of AM2, released days ago, and we have also seen increased performance with each spin of the AM2 CPU.

The design of the test bed is to assure, as much as possible, that the only difference between 939 and AM2 test systems is in the memory subsystems. This includes using the latest FX-60 X2 processor with the most recent DDR memory controller adjusted to the same speed as the AM2 X2 processor. Both motherboards are also based on similar NVIDIA chipsets, and all testing was done with the same Hitachi 200GB hard drive using the same OS installation. The MSI 7800GTX video card was used for testing in both systems. We also had NVIDIA 7900GTX and ATI X1900XT video cards available for testing, but we used the 7800GTX for easier comparison to results from other recent motherboard and memory reviews.

System Configuration
Processor: AMD AM2 X2
AMD FX-60 (X2) adjusted to match AM2 processor speed
RAM: OCZ EL PC2-8000 XTC (DDR2-1000, 2x1GB)
Crucial CLIII5N.32 PN56278 (DDR-500, 2x1GB)
Hard Drives: Hitachi 200GB SATA2
Video Card: MSI 7800GTX 256MB
Video Drivers: NVIDIA ForceWare 84.21
Power Supply: OCZ PowerStream 520W
Operating System: Windows XP Professional SP2
Motherboard: Pre-Release AM2 motherboard based on NVIDIA chipset
Asus A8N32-SLI Deluxe

While the speeds of top DDR and DDR2 are different, we tried to match other factors within memory as much possible. Both DDR and DDR2 were 2 GB kits consisting of 2x1GB dimms. DDR was top-line DDR500 tested at the fastest DDR400 2-2-2 timings; DDR2 was top-line DDR2-1000 tested at the fastest DDR2-800 3-3-3 timings. DDR memory that performs at DDR400 2-2-2 is a premium part and it was compared to a premium DDR2 part.

A more mainstream comparison would have been DDR400 3-3-3 to a DDR2-667 4-4-4 pushed to DDR2-800. The performance differences in the mainstream parts would have been similar, but they would not really reflect the state of the memory market in about 6 weeks. We know that all the top memory vendors plan new DDR2-800 high performance and mainstream parts for the AM2 launch, and offerings at the top of mainstream and high-end will be different in a few weeks. The OCZ PC2-8000 we used for testing, however, is a just-launched DDR2 memory based on what is widely expected to be the best performing DDR2 memory chips available for the near future. This top to top comparison should therefore provide a clear approximation of real performance when AM2 launches.

There is always room for some unexpected AMD announcements, but as Anand explained in his article about the April spin of AM2: ". . . according to internal AMD documents, AM2 CPUs are going to start being sold to distributors starting next month, leaving very little time for significant changes to the CPU to impact performance. We feel that now is as good of a time to preview AM2 performance and put things into perspective as we're likely to get before the official launch." We all can hope for a surprise from AMD, but with distributors receiving parts in less than a month and with official launch just 6 weeks away, we are probably testing what is very close (if not identical) to the final AM2 part.

Index Socket 939 Fast DDR-400 vs. AM2 Fast DDR-2


View All Comments

  • peternelson - Saturday, April 15, 2006 - link

    No I don't work for VIA or Transmeta but I do work in the IT Industry ;-)

    Efficeon chips were used in Orion Multisystems DT-12 and DS-96 cluster in a box computers and some notebooks.

    Whilst they have low power, they do lack performance for some applications compared to the latest chips. But using VLIW based code-morphing they do indeed run x86 code.

    Just call it a "good idea" rather than "unique" ;-)
  • Bladen - Friday, April 14, 2006 - link

    Although DDR2 667 at 3-3-3 doesn't seem that common, all I can find is DDR2 667 4-4-4 or 5-5-5. Here in Australia anyway.

    Maybe when AM2 is released a rehash article featuring the higher latencies is in order.
  • Gary Key - Saturday, April 15, 2006 - link


    Although DDR2 667 at 3-3-3 doesn't seem that common, all I can find is DDR2 667 4-4-4 or 5-5-5. Here in Australia anyway.

    In our recent experiences with Infineon based DDR2-667 modules rated at 4-4-4, the majority of these modules will run at DDR2-667 with 3-3-3 settings with a voltage setting around 2.2V. Your mileage will vary based upon supplier but going with one of the more performance oriented providers will usually result in the better timings.

    We fully expect a wave of higher performance DDR2 modules to be launched in conjunction with the AM2 product. The majority of these new modules settling in around the DDR2-667 and DDR2-800 levels or above as we recently witnessed in our DDR2-1000 article -">DDR2-1000 goes Higher.....
  • AnandThenMan - Friday, April 14, 2006 - link


    This may change in the future, but for now the move to AM2 and DDR2 memory looks like it will yield far too little in performance improvements to keep AMD competitive in the upcoming marketplace.

    It will be interesting to come back to this statement after AM2 and Conroe are out in the wild to see how accurate it was.

    Interesting article, but nothing very surprising to me. The Athlon64 core is pretty much at its computational limit at a given clock, feeding it with more memory bandwidth does little. Which means that early adopters of the AM2 platform will get 939 performance with an updgrade path, which is not too shabby.

    Conroe better live up to expectations though...
  • Wesley Fink - Saturday, April 15, 2006 - link

    It would be a very pleasant surprise if AMD has us all in the dark and launches a Conroe competitive part or a Conroe-killer. Competition is good for buyers, especially when performance is very close. The close performance results in lower prices, as we are now seeing in the ATI/nVidia video cards from the most recent generation.

    However, we have to evaluate things with the best information we have available on time to Fab, launch dates, and the available revs that have been provided to AMD partners to design their companion products for the AM2 launch. There is always room for an unexpected surprise, but it looks less likely the closer we get to 6/6/06.
  • Viditor - Saturday, April 15, 2006 - link

    I have no doubt that AM2 is a very weak at AMD said as much in their recent conference call.
    The only critique I have would be of the line

    the move to AM2 and DDR2 memory looks like it will yield far too little in performance improvements to keep AMD competitive in the upcoming marketplace

    You should have added the word "desktop" before marketplace as the server marketplace should still be solidly AMD, and we have yet to see what will happen in the mobile space...JMHO
  • Wesley Fink - Saturday, April 15, 2006 - link

    A very fair comment. I added the "desktop" qualifier since it makes sense. Reply

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