What is the precision of cudaEventElapsedTime()?

cuda, gpu

Solution

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.

Problem

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

Original source