3 Replies Latest reply on Mar 14, 2011 11:56 AM by himanshu.gautam

    Multpiple GPUs and GUI freezing



      I've a workstation with 2xHD5770 (only the first one has a monitor connected), Linux UBUNTU 10.04, ATI STREAM 2.2, ATI DRIVER 10.9.
      I tried to do the following:
      - inside one shell I've set "export DISPLAY=:0.0" and I've run a simple shell script display the DATE every second
      - inside a second shell I've set "export DISPLAY=:0.1" and I've run the MatrixMultiplication program using large matrix (5120x5120 each)

      Result: during OpenCL MatrixMultiplication program execution (4 secs overall) I had the freeze of both the program inside the 1st shell and the Ubuntu Desktop.

      Any suggestion to avoid this "side effect" ?
      I would expect to not have any hang since I've used the second 5770 with no display connected.

      Thanks for help.



        • Multpiple GPUs and GUI freezing


          Do you still face the problem? Are you able to run opencl programs on a GPU which is not connected to display. It might be the case that you are actually running everything on the same gpu and hence things serialize.

          Can you confirm that you observe the behaviour you reported with latest SDKs and Driver?

            • Multpiple GPUs and GUI freezing


              To be honest, since I had that problem I decided to move to NVIDIA considering also that NVIDIA Cuda and OpenCL do not require a running X session.

              I was very disappointed also because I know that my 2 HD5770 are much powerful that my 2 GTS450.

              Do you think that now my problem could be overcome ?


              Kind regards,