I have system:
OpenSUSE 11.2 amd64, ATI driver 10.7, Stream SDK 2.2, 2x ATI HD 5870(connected in 1st and 3rd slots), NVIDIA GTX470(7th slot), ASUS P6T7 WS SuperComputer , i7 , 3x2GB 1066 DDR3. One monitor connected to each ATI card and noone to NVIDIA.
I've installed ATI and NVIDIA drivers . I've done aticonfig --adapter=all --initial -f.
I've login on init level 3 under "root" and done "startx" so i could see all 4 OpenCL devicesin ./CLinfo. 1 NVIDIA 1 CPU and 2 ATI GPU after connecting on ssh under root.
I run my one OpenCL program in witch I choose OpenCL device to run.
if I run two instance of my program one on NVIDIA GPU and one on ATI GPU, all works fine programs run parallel.
But if I run two instance of my program both on ATI GPU, IN PROFILING i could not see difference execution time of kernels but total working time of program increases in about 2 times.
I've attempted to set
"export DISPLAY=:0.0" for one instance and "DISPLAY=:0.1" to another in this case my programs see only one ATI GPU device for each instance.
in case "export DISPLAY=:0" for both instance each of them see both ATI GPU card so I can choose one gpu for each instance.
But both case didn't solve my problem. Total execution time increased in about 2 times.