topic SSE2 based FFT in Intel MKL in Intel® oneAPI Math Kernel Library

SSE2 based FFT in Intel MKL

dtrumer — Mon, 29 Dec 2003 19:23:17 GMT

Hello,

while reading the MKL description - I could not understaned whether the MKL FFT is based on SSE2 or not. This can effect the performance dramaticly.

Thanks,

Dror

Re: SSE2 based FFT in Intel MKL

TimP — Wed, 31 Dec 2003 22:06:18 GMT

Most likely, the double precision FFT functions in the p4 library will be SSE2. You could test p4 against generic architecture versions on your application.

Re: SSE2 based FFT in Intel MKL

Wendy_Doerner__Intel — Thu, 01 Jan 2004 06:29:44 GMT

The Intel Math Kernel Library Reference Manual, that is in the doc/mklman61.pdf file in the Intel MKL 6.1 installation, does state on page 1-4that the DFTs are optimized to take advantage of processor specific SIMD extensions. To see the speed up for your application; the suggestion to run it with the generic processor codeand compare it to your processor is a good one. Note that the DFT functions are the ones continuing to be optimized for new processors (as opposed to the FFTs).

Re: SSE2 based FFT in Intel MKL

Intel_C_Intel — Fri, 09 Jan 2004 05:15:28 GMT

The power-of-two FFTs do use the SIMD hardware, both for single-precision and double-precision transforms. Up until now the mixed-radix transforms (DFT) have not used the SIMD hardware for non-power-of-two transforms, leading to a significant difference in performance between, say, a 1024-point transform and 900-point or 1152-point transform. With the 7.0 beta software, there are dramatic improvements in those non-power-of-two transform lengths.