Sorry for posting several topics in a row, but I really can’t fgure out what’s going on.
I have recompiled my program with 1.1 and see approx. 2.5x performance degradation :(
CUDA profiler gives folowing results:
- for SDK 1.0 with 162.01 drivers:
memcopy,2.528 memcopy,2.400 _kernel,6005.313,6018.627,1.000
- for SDK 1.1 with 169.09 drivers:
memcopy,2.496 memcopy,2.944 _kernel,6007.840,15108.581,1.000
For some reason cputime is 2.5x the gputime, which explains the slowdown.
This problem occurs only if I have some other CPU-intensive process running in background (with idle priority), even if I run my program at normal priority. CUDA 1.0 seemed to respect host process priorities more or less, at least there were no such degradation caused by processes running at idle :(