6 Replies Latest reply on Jun 8, 2010 12:08 PM by afo

    OpenCL and Crossfire

    Raistmer
      Need Crossfire to be disabled when different GPUs are used separately for OpenCL?

      AFAIK NV's SLI technology should be disabled when CUDA-based apps used.
      What about Crossfire and OpenCL (or Brook) based apps?
        • OpenCL and Crossfire
          nou

          there is some issue if is crossfire enabled. so i recomend disable crossfire.

          • OpenCL and Crossfire
            Raistmer
            Is it possible for 5970 GPUs to disable Crossfire? And how to do that if it's possible?
              • OpenCL and Crossfire
                dominik_g

                I think you only need to disable Crossfire when you have multiple cards, not GPUs. I have two 5970s and I had to remove the Crossfire cable that connected the cards, but there's nothing you need to do about the two chips on your card.

              • OpenCL and Crossfire
                Raistmer
                First of all, it's not my card so I was not aware that 5970 is x2 card actually. With 4xxx generation such GPUs were clearly marked as x2 (4870 and 4870 x2).
                And this technology can't be disabled in software ?
                  • OpenCL and Crossfire
                    dominik_g

                    If you're only talking about a single 5970 card (which contains 2 GPUs), then you don't have to disable anything, as far as I know.

                    It's only problematic when you have two cards. Then you physically have to remove the Crossfire cable. I'm not aware of a software solution in this case...

                      • OpenCL and Crossfire
                        afo

                        Hi,

                        I have 2xHD5970; to disable crossfire in windows, when CCC detects a second card, it enables a crossfire menu; in it you have a checkbox to enable/disable crossfire. In linux you have an aticonfig command to do that.

                        Note that in windows, if I disable crossfire, I only find 3 GPUs in clinfo, to see 4 GPUs I have to enable crossfire (My development cycle starts in windows and the pass to linux, so I didn't checked it in linux yet)

                        hope this helps,

                        Alfonso