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Memory Timings Analysis

Posted by CmdrTaco on from the squeezing-out-the-fps dept.

keefe007 writes "It's generally known that smaller and more aggressive memory timings combined with higher clock speeds leads to higher performance, but for the most part, the increase in performance from tweaking each individual setting is relatively unknown. Perhaps in a bit too ambitious move, I set out to examine the impact of each individual memory timing and clock speed on overall performance. Find out the results of the tests at Techware Labs."

6 of 159 comments (clear)

  1. cas vs bus speed by kochsr · · Score: 5, Insightful

    so what i got out of that is that increasing the speed of the memory (from 133 -> 166) is a much larger difference than bumping down the cas latency. i think i'd rather have memory on a faster bus than at a lower cas then.

    but people will always say they have their stuff at the most agressive timings just to say that they are there, even though the average performance increase is only 0-2%

    1. Re:cas vs bus speed by photon317 · · Score: 5, Insightful


      Yeah, that's a problem I have with this guy's test results. He's taken all the memory parameters which have very different purposes and effects, and rated them all on a scale of percentage increases in memory bandwidth.

      The important effect of dropping CAS latency is that it improves memory response time on a small request - it's not meant to really give a big boost to bulk bandwidth.

      You can think of the tradeoffs from spending a fixed dollar amount on clock speed boosts vs lowering CAS times as kinda like the difference between going RDRAM and going SDRAM. RDRAM had much higher bandwidth, but the latency sucked. SDRAM had lower bandwidth, but also had lower latency.

      So wrap it up - this test is uninteresting because it rated all those parameters based on how they affected bandwidth, when really only the clock speed speed has a significant impact on bandwidth - a lot of the other parameters are really more about latency and responding well to certain patterns of access.

      --
      11*43+456^2
  2. Results = Waste of Time? by Baron_911 · · Score: 4, Insightful

    Wow, considering all the settings that were tested, and the only improvment beyond 1% was the Clock Speed, seems like the rest of it was kinda a waste...

    --
    Polaroid. See what develops!!
  3. What beats me... by jkrise · · Score: 4, Insightful

    Is the fact that accountants and finance managers (decision makers in PC buying deals) talk as if they understand all these things better than sysadmins. SDRAM, DDRRAM, RambusRAM, L2 cache, on-chip cache and all that marketing crap is heavily used by these decision makers.

    Last year, I did a demo of a Via system with SDRAM and it did about 40% faster than a DDR-RAM board. The VP-Fin chap has become highly suspicious of any memory performance graphs or numbers, these days. And in true BOFH style, I've got decision-making rights on all PC purchases.

    Thanks to all the confusion.

    --
    If you keep throwing chairs, one day you'll break windows....
  4. this guy by daveatwork · · Score: 5, Insightful
    has was too much time on his hands. WAY too much time.

    Speaking as an engineer, I do hate buying new stuff because its cheaper to do so rather than spending time tweaking the old stuff, but 100's of combinations, for a few % increase? Even I would be perfectly happy in paying the money rather than loosing 0.05% of my life!

  5. Re:Sounds like an Ad... by Lafe · · Score: 5, Insightful

    If Dell sent you, gratis, their high-end gaming machine for you to review and post about on your blog (assuming you have one), would you not mention the fact more than a couple of times in thanks for the free machine?

    Sure it's advertising for whomever the vendor was, but its also a sponsorship of something that the author might have had to pay for himself. Or might have had to do without.