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
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  • phial - Thursday, July 05, 2007 - link

    "Comments are often made that any evaluation of AM2 should include overclocking. Those theorists argue that the faster processor clock will move AM2 to the higher "bus" speeds that make for better efficiencies of the DDR2 memory controller - or something along those lines."

    OK who hired this guy? He knows NOT what he speaks of. Its apparent through the entire review.
    Reply
  • phial - Wednesday, July 04, 2007 - link

    "This will likely shift to patterns similar to those seen in bandwidth positioning as the AM2 memory controller is further refined and game patches make better use of AM2 capabilities."

    Wow... and your posting hardware reviews on a high traffic website.. amazing...
    Reply
  • Zebo - Tuesday, April 18, 2006 - link

    I get everest of 42ns 2-2-2 @ 200 with FX60 speeds on DFI NF4. I get 36ns when cranking up to 250mhz 2-2-2. And that reminds me - I guess you did'nt want to embarres AMD's new chip too much by putting old, supported, DDR 550 @ 2-2-2 in there huh?

    What a dog this change is.
    Reply
  • Wesley Fink - Wednesday, April 19, 2006 - link

    Actually our Beta motherboard and CPU were not 100% stable at 275. Also I don't have any memory that will do DDR550 (275 clock speed) at 2-2-2. Perhaps you mean another speed or other timings.

    Our Crucial 2GB kit can do DDR500 at 3-2-3 timings, but our DDR2-800 memory is also capable of doing 3-2-3 at some speeds if the beta motherboard had supported those timings. That's the reason we compared 3-3-3 500, which should be very very close to each memory's top performance and a fair comparison.

    Our latency testing was at a slower speed than your FX60, which is why you got lower latency numbers. We did, however, set both the DDR and DDR2 platforms to the exact same speed and ratios for all the benchmarking. The results comparison was as fair as we could make it.
    Reply
  • spinportal - Tuesday, April 18, 2006 - link

    Let's see.. the 1GB PC-4400 DDR-550 kit is roughly 200$US for 2.5-3-3 timing. The DDR2-667 PC-5300 1GB kit is ~180$US for 3-3-3 timing for use to OC to DDR2-833. Unless I'm missing something, I don't understand your beef about spending $20 more for equal performance and using more juice. Reply
  • puffpio - Monday, April 17, 2006 - link

    I can see gaming benchmarks being VERY graphics and cpu calculation intensive...
    but in terms of the bus between the cpu and main memory..i dont see it as that intentive

    I wonder if a multitasking benchmark w/ lots of datasets would show off the increased bandwidth? (giant spreadsheets, databases, image processing, video encoding, etc etc)
    Reply
  • shady28 - Tuesday, April 18, 2006 - link


    "Real world" single user and light multitasking apps aren't going to use up the bandwidth. A heavy duty multitasking environment is what's needed to really test the benefits of dual core + DDR2. The thing is, this doesn't really describe what most PCs spend 99% of their time doing.

    That said, Conroe does look promising, and I'm interested to see what AMD can come up with to counter it. The initial performance advantages, according to *Intel* benchmarks, are pretty significant. Hopefully AM2 is just laying the groundwork for faster processors from AMD. Still, I can't help but think the performance boosts we've been getting since about 2001 (3.06Ghz P4 HT) are marginal, and that this is yet another marginal boost.
    Reply
  • NullSubroutine - Monday, April 17, 2006 - link

    I am still convinced that the transition from DDR to DDR2 is primiarily because it unifies the memory production industry, lowers power for server and mobile areans, increases memory bandwidth for upcoming memory hog (ie vista), and servers as a platform of increased memory capability. As for the last point I think most of us believe that quad core CPU's may use more memory bandwidth and the original DDR may act as a bottleneck for the system. I also think it is clear that memory bandwidth is not a bottleneck for AMD, but I applaud them taking care of a potential bottleneck before it exists, unlike Intel who has continuelly bottlenecked their CPUs by insuffient memory bandwidth. Reply
  • NullSubroutine - Monday, April 17, 2006 - link

    quote:

    (ie vista), and servers


    should say serves obviously.
    Reply
  • eRacer - Sunday, April 16, 2006 - link

    Was the DDR2 using a 2T command rate and was the DDR-400 tested using 1T? Is there an option to change the command rate on the AM2 motherboards? I believe at least some Pentium DDR2 motherboards with NVIDIA chipsets have the option to use a 1T command rate.

    I've seen some Sandra 2005 standard memory tests gain 500MB/s or more just by using 1T instead of 2T. A gain like that would allow DDR2-533 1T to score higher than DDR2-800 2T in the Sandra 2005 standard memory test. If DDR2-800 could use a 1T command rate the performance gain in the non-synthetic benchmarks might be a few percent higher on average. While that doesn't sound like much it would be roughly double the DDR2-800 performance advantage over DDR-400 in this review.
    Reply

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