Maybe something is fubar'd in my XP install but

TexTex Dallas/Ft. Worth
edited January 2004 in Hardware
Remember I was sorta amazed at the memory bandwidth numbers I was getting on my dual opteron with old pc2100 memory? I was getting like 3200 to 3400 with regular 2.5 pc2100 ecc ddr on the sandra memory bandwidth thing....

I just tested it on win2003 with amd64 version of win2003 and it rolled a 4500. Reboot to XP and its a 3300???

The cpu benchmarks are no faster and remember this is the 32bit version of sandra benching it and not a 64bit version also so the numbers seem weird.

tex

Comments

  • Straight_ManStraight_Man Geeky, in my own way Naples, FL Icrontian
    edited January 2004
    Well, 64 bit code CAN optimize by using two 32 bit "words" per command level process chunk, and that can cause what you see. BUT, without that you get poorer backward compatibility. In this case, I think what you have is that the combined codes process so much faster that they process in less time, and this will throw benchmarks off. the only ohter thing I can think of is thta you got some radically fast and underspeced DIMMs. Have you tried with other DIMMs to see if you get a similar proportionate change??? If so, is effectiveness of code processing that is throwing the wait state timing bases off.... If NOT, you got real lucky with possibly some mislabelled RAM stick modules or some modules that work much better than average.

    I am figuring you have a native 64 bit CPU to make the code thing happen, BTW. And big sticks of RAM that are 64x64 mapped or 64x128 mapped.

    John.
  • TexTex Dallas/Ft. Worth
    edited January 2004
    Dude this is the same mismatched pc2100 ecc reg stuff I been buying off ebay for 25 bucks a stick. Works rock solid in teh mpx duailes. Somes HP somes IBM and somes infineon. I have asked sandra for a beta version of their new amd64 version of the benchs. I didn't think you would see squat for speed differance with out the benchs and apps being 64bit for the most part. maybe ten percent but nothing wild. The cpu's and drives and other pieces all bench about the same. Only the memory bandwidth went up by 33 percent. Sometimes by almost half. I hit 3200 on XP and almost 4500 on win2k3 64AMD.

    Tex
  • mmonninmmonnin Centreville, VA
    edited January 2004
    Wow thats a lot more BW just with an 64 bit OS.

    XP is a RAM Hog tho.
  • TexTex Dallas/Ft. Worth
    edited January 2004
    I'm not convinced its the 64bit OS or rather improvements in win2k3 itself in how it uses the chipset also. I'll install a 32 bit version of win2k3 tomorrow.

    And hopefully I'll hear back from Sandra about getting a beta of their benchamrk software optimized for 64bit amd also.

    tex
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