I'd like to compute the throughput of FFT and IFFT using cuFFT.
I think that it should be O(B n log n) where n is the signal length and B is the batch size.
The throughput in GFLOPs should be = 10^-9 * B * N * log N * c / runtime.
The thing is how to find out c (the constant here).
I found some people use c = 2.5 in the case of FFT, and c = 5 in the case of IFFT. Is this correct?