Memory Test Configuration

The new AM2 platform offers several significant advantages as a DDR2 memory testbed. Unlike our Intel 955EE Presler, which has ratios of just 12x and 13x, the AM2 platform provides a full range of multipliers below the rated speed. Offsetting this advantage, however, is the first generation of AM2 on-processor memory controller, which does not support any memory timings below 3, where the Intel platform supports 2 settings for RAS-to-CAS and RAS Precharge. In addition, we have yet to examine an AM2 board that supports DDR2-1067 as a memory speed option and some of the newest DDR2 memories coming to market are rated at DDR2-1067. The upcoming Core 2 Duo also needs to be examined in the mix, since the Extreme version is expected to offer a wide range of available ratios, as well as continued support for 2 memory timings and DDR2-1067 and possibly even higher memory ratios.

After looking at all available options, the decision was made to stay with the Intel platform for testing memory, substituting the updated Asus P5W-DH board for the earlier P5W-D2. The most recent P5W board fully supports Core 2 Duo (Conroe) as well as the current Presler chip.

The decision was also made to drop overclocking tests at 1:1 DDR2 memory until Conroe is available. Testing with the 955EE (3.46GHz) was limited by the low overclocking wall of this Presler based chip in our standard setup. With more ratios and the reported excellent overclocking of Core 2 Duo we do not expect an overclocking wall to be a hindrance with a Conroe chip driving the test bed. The Intel Pentium 955 Extreme Edition CPU, a 1066MHz FSB dual core solution containing 2MB of L2 cache onboard, was continued as our standard memory test CPU until Core 2 Duo is launched. The EE chips have the advantage of operating at 1066FSB, or 266 base, which raises the 1:1 memory to DDR2-533 instead of the DDR2-400 that is the 1:1 match for 800FSB. Conroe will also operate at 1066FSB

The Asus P5W-DH supports the same wide range of memory speeds and FSB options as the earlier model. A full review of the updated Asus P5W-DH Deluxe is in the works and will be appearing at Conroe launch.

ASUS P5WD2-E Premium Motherboard
Memory Configuration Options
  Auto DDR2-400 DDR2-533 DDR2-667 DDR2-711* DDR2-800* DDR2-889* DDR2-1067*
FSB 1066 X X X X X X X X
FSB 800 X X X X   X    
FSB 533 X X X          

Our memory test bench uses the following components:

Memory Testbed
Processor: Intel 955 Extreme Edition at 13X Ratio
(3.46 GHZ dual core 65nm CPU)
RAM: Buffalo FireStix PC2-8000C5
Crucial Ballistix PC2-8000
OCZ EL PC2-8000 XTC
Hard Drives: Hitachi 250GB SATA2
Seagate 7200.9 ST3500641AS SATA NCQ - 16 MB Cache
Video Card: EVGA 7900GTX
Video Drivers: NVIDIA ForceWare 91.31
Power Supply: OCZ PowerStream 520W
PC Power and Cooling Turbo-Cool 850-SSI
Operating System(s): Windows XP Professional SP2
Motherboard: ASUS P5W-DH Deluxe
BIOS: AMI version 0504 June 30, 2006

Since the P5W-DH is an updated board, OCZ EL PC2-8000 was retested. Memory bandwidth and timings did not change with the move to the Asus P5W-DH, but we did find game benchmarks were 1 to 2 FPS faster on the newer board. Only results from memory reviewed or retested in the new memory platform is included in the comparison charts. The Buffalo FireStix DDR2-1000 and Crucial Ballistix DDR2-1000 are both based on the newest variant of the Micron D die. So is OCZ EL PC2-8000. All three memories are rated at DDR2-1000.

Product Specifications and Information Buffalo PC2-8000 C5: Stock Memory Performance
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  • JarredWalton - Friday, July 7, 2006 - link

    We're working on more memory reviews, and Corsair's offering will be reviewed soon.
  • araczynski - Monday, July 10, 2006 - link

    didn't know that was an option, but that's ok, with the adblock solution i get to kill many birds with one stone.
  • araczynski - Friday, July 7, 2006 - link

    ...i'm getting fed up with the damn intellitext ads all over the place, anyone know of a surefire way to block that crap?

    TIA
  • araczynski - Friday, July 7, 2006 - link

    NM, found adblock for firefox, brilliant!
  • JarredWalton - Friday, July 7, 2006 - link

    Another option is to simply http://www.anandtech.com/siteinfo.aspx?intelli=y">turn it off in your site preferences. :)
  • lopri - Friday, July 7, 2006 - link

    Excellent review in that it shed light on DDR2 testing methodology on Intel platform. I should admit that I'd been quite ignorant about DDR2 scaling to this date. This article exaplains alot about the way Intel platform works and how dividers are used - in plain English. It seems, in a sense, it's easier to test memory on Intel platform, especially once Conroe arrives, with so many dividers available at any given CPU clock.

    Thanks for an excellent review. BTW, when can we expect the P5W-DH review and/or DFI 975X Infinity review?

    lop

    *nitpick1 : On page 5, there is a typo. ;)
    quote:

    With ratios, memory speed remains constant at 3.46GHz and memory speed is varied by choosing different ratios


  • Wesley Fink - Friday, July 7, 2006 - link

    Thanks, Lopri. The typo is now corrected.

    Now that AMD has moved to DDR2 with AM2, memory dividers and memory speeds work exactly the same, with standard supported speeds to DDR2-800.

    The P5W-DH review will post next week.
  • semo - Saturday, July 8, 2006 - link

    why don't you make a dedicated error reporting section for each article?
    last page fifth paragraph:
    quote:

    DDR2 Memory on the Intel platform, however, is by definition Double Data Rate, so a 266 base setting is 533 (2x266).
    shoudln't that be "amd platform"
  • Wesley Fink - Saturday, July 8, 2006 - link

    We were talking about how Intel handles memory speed which is why AMD was not also mentioned. DDR-533 is DDR-533 on BOTH the Intel and AMD platform. However, the CPU clock speed on the AMD platform is 400, while the bus speed on the Intel is 1066. AMD double pumps 200 on the clock to achieve 400, while the latest Intel processors quad pump 266 to achieve 1066. The BASE speed is still 200 AMD and 266 Intel.

    1:1 on the AMD is therefore DDR2-400, but Hyper Transport and the on-chip memory controller on AM2 means the memory speed or ratios don't really matter. There is no penalty for running AM2 at ratios, but there is a very slight penalty for running Intel at other than 1:1 (DDR2-533) - in the range of 1% to 5% memory bandwidth reduction.

    The AM2 has massive DDR2 memory bandwidth, but it is not memory-starved and really can't use the extra bandwidth in the current CPU design. It might matter more in future AMD designs.
  • semo - Sunday, July 9, 2006 - link

    ok thanks i think i get it now. and it's a shame amd can't take advantage of the advances ddr2 has made (apart from the reduction in penalty going from ddr to ddr2)

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