cudaSetDevice() too slow

Accelerated Computing CUDA CUDA Programming and Performance
1

Hi
How much time we pay for cudaSetDevice() function.
In my program, cudaSetDevice() takes me 75.214(ms).
It is too slow or I did some thing wrong?
Thank you.
:)

2

cudaSetDevice() should only be called once… it should not be on the critical path, so you shouldn’t care if it is slow. Is there some reason it matters?