Can NaN value slow down the CUDA computation (Math operation)?

Accelerated Computing CUDA CUDA Programming and Performance
1

Hello,

I am testing now a kernel which takes long time to compute output values and I just see that they are all NaN values. Please can you tell me if those NaN values can drastically slow down the math operation inside Cuda kernel?

Thanks

Abdoulaye

2

No.

3

As opposed to many CPUs, GPUs handle all special floating-point operands at full speed. At least that is the case all the way to the Pascal architecture, which is the latest one I have used.

Depending on what your numerical algorithm does, the presence of NaNs could cause it to iterate indefinitely, however.

4

@njuffa Thank you for the details. I just realized that the Nan effectively affects the computation time.