1 Reply Latest reply on Jun 24, 2013 7:00 AM by zhangjingtian

    OpenCL same cards but different transfer rates.

    zhangjingtian

      Hi,

         I have one hd7990 card in my pc, after crossfire it, in the opencl code, i can find two hd7970 GPU devices.

         But when i transfered data to them, they are in different rates. One is almost double time of another.

         Attachments are the CodeXL screen capture pictures.

         Anybody can tell me why?

         Thanks.

        • Re: OpenCL same cards but different transfer rates.
          zhangjingtian

          Hi,

               It seemed that i had found the solution. I tried to reset the frequency of the card using 'aticonfig --odsc' command, and it turned out that both cards inside the hd7990 nearly work at the same data transfer rate.

               But I found my hd7990's Pci-e data transfer rate can just only reach to 4GB/s in one direction(each hd7970 inside it reached to 2GB/s), I know the Pci-e x16 can work to the peak bandwidth 8GB/s one direction, how can i raise up my 4GB/s rate?

               Thanks.

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