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
Comments Locked

24 Comments

View All Comments

  • Wesley Fink - Monday, July 10, 2006 - link

    Crucial has advised AnandTech that "all of Crucial's memory products come with a lifetime warranty". We have updated the review to reflect this information on the Crucial warranty.
  • MacGuffin - Saturday, July 8, 2006 - link

    quote:

    DDR2 1067 (2:3) Performance


    It should read DDR2 1067 (1:2) Performance.
    This needs to be fixed on Page 10, along with the link on Page 9 that points to page 10, and the Article Index drop-down list.

    Excellent Review, nonetheless.
  • JarredWalton - Saturday, July 8, 2006 - link

    Fixed, thanks. :)
  • PLaYaHaTeD - Saturday, July 8, 2006 - link

    I thought since the front side bus of the 965 is 1066, it would be the 'Holy Grail' to have the memory running at 1066 as well. Wouldnt this make it synchronous again? What am i missing?
  • MacGuffin - Saturday, July 8, 2006 - link

    Synchronous Operation (meaning FSB:DRAM Ratio at 1:1)
    266MHz FSB -> 266MHz RAM Speed -> 533MHz DDR2

    The 1:2 Divider (which isn't synchronous) yields 1066MHz
    266MHz FSB -> 533MHz RAM Speed -> 1066MHz DDR2

    Am I right or have I gotten it wrong? I haven't used Intel since I got this Socket 754 I am typing on.
  • poohbear - Friday, July 7, 2006 - link

    hello, just wanna clarify if the a64 can actually use any of the extra bandwidth provided by ddr2 800+? is it only for bragging rights or is the a64 actually saturated for memory bandwidth & therefore this higher bandwidth provides performance improvements? thanks in advance.
  • Wesley Fink - Friday, July 7, 2006 - link

    The A64 does exhibit tremendous DDR2 bandwidth with the on-chip DDR2 memory controller, and memory bandwidth continues to improve as speed goes up. However, as we found in our testing of the AM2 in the DDR2 vs. DDR article, the AM2 design is not memory bandwidth starved, and the extra memory bandwidth makes almost no difference in real-world performance on the current AM2 platform. The improved memory bandwidth may make more of a difference in future AM2 designs.
  • lopri - Friday, July 7, 2006 - link

    I thought this issue was mentioned in the article but I couldn't find it when I re-read it. I know on intel system the memory running slower than 1:1 will result in small penalty, but how about memory running faster than FSB? I vaguely remember that I've heard somewhere it's better than 1:1 cause that way memory "pushes" or "rushes to" FSB. Another theory I've heard is that faster memory can make up for possible performance loss on FSB subsystem, leading to less CPU idle time. According to this review, regardless the ratio, the performance seems to increase linearly to memory speed increase.

    So the questions being:

    1. Is 1:1 the most ideal ratio without "waste"?
    2. Or a slightly higher memory speed than FSB (such as 4:5) better than 1:1, preventing possible CPU idle time and "pushing" the data at the same time?
    3. Or under the same CPU/FSB speed, the faster the memory the better the performance - indefinitely, taking advantage of faster memory speed?

    I would think No.3 doesn't make sense because of the very FSB. In the end the FSB has been what's limiting both CPU and memory on Intel system. How could the performance get benefit from 3:5? In an ideal world there should be waste of 2. (5 - 3 = 2) Is the performance even better with 1:2? I can't imagine the FSB system being only 50% efficient, but is that the case?
  • Gary Key - Saturday, July 8, 2006 - link

    Lopri,

    Please email me about this subject. Short story is 1:1 or 4:5 are your best ratios for the Intel platform at this time although this will change depending your choice of Conroe model. We will go over this in more detail shortly and I will respond here further once I complete some article testing.

    Thanks,
    Gary
  • Locust - Friday, July 7, 2006 - link

    Very good article, but I have a question. How come you guys did not review Corsair's PC8500 memory modules. I have been using 2GB kit(2x1GB) for over a month and getting timings comparable to OCZ's. DDR2 800 runs at 3-3-3-5 memory settings on same mobo.
    Best si DDR 1000 @ 4-4-3-8 @ 2.2 recommended voltage.

    Good to see more vendors offering these memory speeds, now let's just hope prices will get under $400 :-)

Log in

Don't have an account? Sign up now