17 Replies Latest reply on Jan 14, 2011 5:51 PM by nou

    What's the maximum number of ATI GPUs officially supported by Windows drivers? #2

    empty_knapsack
      As first topic got corrupted

      I cannot no longer see the whole original topic I've created:

      http://forums.amd.com/devforum/messageview.cfm?catid=328&threadid=141888&enterthread=y

      As some xml tags spawns in the middle and Opera and IE9 refusing to show page properly, so I'm re-quoting everything here:

       

      Originally posted by: empty_knapsackYear ago it wasn't possible to use more than 4. I've seen some reports about working 3x5970 configs since then but under Linux.
      What's about Windows? Was 4x limit been increased finally?
      One of our users trying to setup 3x5970 system and even with dummy plugs/monitors attached to each of 5970 DVI ports it fails to operate properly -- system simply lock ups after several seconds of work. There no problem with PSU, so this isn't the case.


      Originally posted by: himanshu.gautamI can confirm Working with 8 GPUs in a system on both linux and windows platform.
      -------------------------
      Himanshu


      Originally posted by: empty_knapsackCan you please provide more details about this system?
      What motherboards was used, what GPUs? Which version of Catalyst was installed, are there any dummy plugs were used to make all GPUs recognized by Windows? Which software you've used to make sure that all 8 GPUs in fact works and producing correct results?


      Originally posted by: himanshu.gautamempty_knapsack,
      The Linux system had following configuration:
      OS: Red Hat 5.3 64-bit
      ATI driver: Catalyst 10.4
      CPU: Two Quad-Core AMD Opteron
      Chipset: NVIDIA nForce Professional 3600 and 3050
      RAM: 32 GB DDR2
      -------------------------
      Himanshu


      Originally posted by: afoHi,
      It's nice to hear that, but this raises a question: what performance do you have compared with 8 GPUs in 8 different computers? And as others asked: what boards were used?
      best regards,
      Alfonso


      Originally posted by: himanshu.gautamempty_knapsack,
      We plugged 8 monitors to these GPUs. CAL's FindNumDevices as well as OpenCL showed 8 GPUs. We also ran a OpenCL reduction program that used all 8 GPUs and got correct result
      -------------------------
      Himanshu



      Now, as Alfonso, I'm very interested to know which GPUs were used and are they working simultaneously for at least several seconds (not as most CAL/OpenCL samples which works just milliseconds) and all producing correct results?

      Also my original post was related to Windows (though Linux support is also interesting) and I'm quite curious which drivers you've used for it, as Catalyst 10.4 was completely broken for Windows and 5970. 2nd core was detected and even can be used for calculations but it runs much slower and produced just garbage instead of real results.

      Also, are you absolutely sure that OpenCL test you've used was correct? I'm asked this because earlier you was suggesting to use SimpleMultiDevice /e as test:

      http://forums.amd.com/devforum/messageview.cfm?catid=328&threadid=139608&enterthread=y

      but later it ends as this test reports OK for any results because of programming error inside.