@delshay
Ok here is result with Cyberstorm PPC 366MHz, 66.7MHz bus speed, 70ns ram, OS4:
FFTDemo
Speed test for FFT + iFFT: (float)
time needed 8362ms for 413696 samples, => .560922145843505x speed @44100Hz/stereo
Speed test for FFT + iFFT: (integer)
time needed 7154ms for 413696 samples, => .655637502670288x speed @44100Hz/stereo
Speed test for FFT + iFFT: (integer handoptimized 68K ASM)
time needed 3357ms for 413696 samples, => 1.39720904827117x speed @44100Hz/stereo