benchFFT is a program to benchmark FFT software, assembled by Matteo Frigo and Steven G. Johnson at the Massachusetts Institute of Technology as part of the FFTW project:
The benchmark incorporates a large number of publicly available FFT implementations, in both C and Fortran, and measures their performance and accuracy over a range of transform sizes. It benchmarks both real and complex transforms in one, two, and three dimensions. The FFT implementations in the benchmark (found in the benchees/ subdirectory) were written by various authors over a period of more than 35 years. Except for small tweaks to get things to compile, we used the unmodified original codes.
This code is rather old and may require some effort to compile on a modern machine. (Run bootstrap.sh first on a git clone to auto-generate the build files.)