Stock Memory Performance

Most of today's motherboards that support DDR2 provide a wide range of memory ratios that match available DDR2 memory. End-users can select the memory ratio that matches their DDR2 memory speed. Our memory testing uses the same approach. We first test all of the stock ratios at the fastest stable timings we can achieve at the given ratio. With ratios, CPU speed remains the same at 2.93GHz in our memory test bed, and memory speed is varied by selecting different ratios.

The memory controller for Intel Socket T (Socket 775) motherboards is in the chipset, instead of part of the processor as in AM2 systems. Therefore, there is the potential for some memory performance anomalies. There is theoretically a small performance penalty for speeds other than a 1:1 ratio (DDR2-533 in this case) on boards designed for Intel processors. However, the actual performance penalty has been found to be very small with minimal impact on test results. As a result memory scales nicely through the various speed options.

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DDR2 memory is then pushed from the highest stock ratio that could be achieved in testing - in this case 1067 - to the highest FSB speed at the stock multiplier. A fortunate accident occurred in test results for the OCZ Flex XLC in that the highest stable memory speed on the P5W-DH of 1172 represents a base CPU speed of 293. By lowering the multiplier to 10 we were able to keep the overclocked memory test results at the same 2.93GHz processor speed. This allows easy comparison of test results at a very high memory speed at the same 2.93GHz. Results for the standard multiplier of 11 are also included at the bottom of the table. These are the results that should be compared to past DDR2 memory test results.

No matter how you slice it, the simple fact is that the OCZ Flex XLC, tested on air cooling, is the fastest DDR2 memory tested so far at AnandTech. DDR2-1172 exceeds the rated speed of DDR2-1150 on one of the most demanding boards available for testing DDR2 memory. To put this in perspective, the previous overclocking champion on this test bed reached DDR2-1116. Flex XLC, at DDR2-1172 is more than 5% faster than the previous best. With these results it was time to see where this memory could go on the new NVIDIA nForce 680i chipset - a chipset that had exhibited some stellar overclocks in our initial chipset launch review.

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On the nForce 680i the OCZ Flex XLC took DDR2 memory performance to a new gold standard. On Air Cooling, Flex XLC reached DDR2-1300 at the rated timings of 5-5-5-18. This is 150MHz above the aggressively rated speed of DDR2-1150 (PC2-9200). The DDR2-1300 speed would be rated at PC2-10400, making Flex XLC the first DDR2 memory to break PC2-10000 in our memory testing.

Memory Test Configuration Memory Bandwidth Scaling
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  • snout - Tuesday, January 23, 2007 - link

    I would like to see the ocz up against the Team Group Extreme 800 mhz c3 sticks at 3.3.3.8. The memory choices at test make it (ocz) look better than it is. Reply
  • ZOOAIRZ - Saturday, December 30, 2006 - link

    Reguarding article:
    http://www.anandtech.com/memory/showdoc.aspx?i=288...">http://www.anandtech.com/memory/showdoc.aspx?i=288...

    Quote:
    "On the nForce 680i the OCZ Flex XLC took DDR2 memory performance to a new gold standard. On Air Cooling, Flex XLC reached DDR2-1300 at the rated timings of 5-5-5-18."

    OCZ Flex with the following stable ratios:

    1) cpu: 3.22 (11x293) FSB: 1172 - linked 1 to 1 - RAM: 1172 Quake4 FPS: 127.3
    2) cpu: 3.03 (7x433) FSB: 1733 -unlinked 1.3 to 1- RAM: 1300 Quake4 FPS: 122.1

    Say one then ups the multiplier as follows and assume it is stable:

    1) cpu: 3.52 (12x293) FSB:1172 - linked 1 to 1 - RAM: 1172 Quake4 FPS: ?
    2) cpu: 3.46 (8x433) FSB:1733 -unlinked 1.3 to 1- RAM: 1300 Quake4 FPS: ?


    Which combo is better/faster overall?

    - 1) Linked (fast) FSB and RAM with slightly higher (+.05GHz) CPU speed
    or
    - 2) Unlinked (raging) FSB and RAM with slightly lower CPU speed?

    This question comes from the following statement found in this article:

    http://www.pcpro.co.uk/phpbb/viewtopic.php?t=17384...">http://www.pcpro.co.uk/phpbb/viewtopic.php?t=17384...

    Quote:
    Now you have your OCed system. Here is something to remember a
    processor running 200*10 =2000MHz and a processor running
    210*9.5=1995MHz yet the second is faster because its running a faster
    FSB so it has more memory bandwidth.(note that if you have to use a
    slower ram speed i.e. using the FSB:RAM ratio of 5:4 you wipe out this
    increase in bandwidth)

    I don't see a FSB:RAM ratio 1.3 : 1 wiping out too much bandwidth but I just don't know. I am just interested in the overall good of playing my favorite games And getting the most out of a PC. If gettting that crazy 1300 speed of the memory just sets a record, that doesn't do it for me.

    Thanks in advance.
    Reply
  • Gannon - Thursday, December 14, 2006 - link

    Could we get better simpler graphs when doing these comparisons? I hate looking at having just these charts, the overlapping colored lines and dots are useful for analysis but not for someone who's time is valuable and simply wants to know whats the best at a glance and thats what you guys should be doing! Serving your users the information they want in the way they want it. Anyone interested in performance is going to go for the highest performing ram, but it's also good for those of us curious to be able to tell at a glance what different ram will buy us.

    i.e. the way firingsquad does graphs or the way you do it ususally when comparing FPS between video cards would be just as useful.
    Reply
  • Beachboy - Saturday, December 09, 2006 - link

    This OCZ Flex RAM is the equivalent of a chrome exhaust-pipe extension on a Hyundai... a $490 one that is, lol. Reply
  • Wesley Fink - Sunday, December 10, 2006 - link

    For the Hyundai analogy to make sense we would have to have a BMW in DDR2 memory. The Flex XLC is as good as it gets, so it is the BMW even though it doesn't go a lot faster. The chrome exhaust extension on the Hyundai would be a matched pair of 2GB value dimms based on Elpida memory chips with flashy heatsinks. You will reach DDR2-800 just fine, but nothing over about 900. It will definitely get the job done.

    Of course the BMW isn't only about speed, and luxury cars sell well despite the fact that you probably would have a hard time justifying "value per dollar" on anything more than a Japanese V6. Some buyers want the handling and flexibility that comes with the best.
    Reply
  • yyrkoon - Sunday, December 10, 2006 - link

    I agree with your analogy for the most part. I guess the only real question is: "is it worth buying". Which of course, you've already answered in the article.

    I would think this memory would be perfect for you guys, in testing potential OC's of systems you're reviewing, other than that, IMO, it would be a waste of money.

    </my_two_cents>
    Reply
  • Wesley Fink - Sunday, December 10, 2006 - link

    The Flex XLC actually DOES go a LOT faster, so the BMW analogy applies, but you don't get similarly big gains in performance with the big speed increases since our DDR2 processors are not particularly sensitive to memory bandwidth.

    It's sort of like a world where a 500 horse power engine doubles your speed, but 80% of the speed increase just goes to fighting the incresed head wind. It does not mean the Flex XLC is not a good design, because it definitely is as good as it gets in current DDR2 designs.
    Reply
  • Avalon - Saturday, December 09, 2006 - link

    It seems to me that it was the 680i that allowed the OCZ Flex to reach an outstanding DDR2-1300, so why not test previous memory modules to see how much further they'd also get on the new Nvidia platform? It seems only fair. Reply
  • Wesley Fink - Saturday, December 09, 2006 - link

    We also tested on our standard platform - the Asus P5W-DH Deluxe - where the Flex reached DDR2-1172 on air cooling. That was the highest ever on that platform - the previous high was DDR2-1111. That was fair, which is why we tested on the current memory test bed.

    As we said in the review, we will add overclocking tests with the 680i going forward, but we will still do base testing with the 975x baord.
    Reply
  • Avalon - Sunday, December 10, 2006 - link

    Right, but my point was that many other modules might have a ton of additional headroom if placed into the 680i platform. I'm not contesting the fact that the Flex reached the highest speeds on the 975x, but that previous modules should be tested on the 680i to see how much of a difference it makes, not just for the Flex. Reply

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