What is the precision of cudaEventElapsedTime()?

Question

Say I invoke a cudaEventElapsedTime() and get the return value of 0.123456. Then what is the exact time it suggests?

Answer 1

As stated in the documentation, the function cudaEventElapsedTime returns the elapsed time between two events in milliseconds. It has resolution of about 0.5 microseconds.

So value 0.123456 indicates that the elapsed time between the specified events is 0.123456 milliseconds.