program run on CPU and GPU

if i run the program on CPU having say 2 cores,which i ran on gpu having many cores and in program all threads ran simultaneously,but .how it will be run on CPU? if same program is run on both GPU and CPU…so it will run only on single core of CPU or both cores of CPU simultaneously …

You’ve already asked this question, and it’s been answered.

Refer to the vendor documentation for the driver you’re using - as anything else is just a guess.