[gct]

FFTW will definitely query cpuid at runtime too, since it's piecing together kernels anyways it's not much more work for it to choose to ignore AVX, etc. If you use the [guru interface](https://www.fftw.org/fftw3_doc/Guru-vector-and-transform-siz...) to configure it to work with split arrays (and maybe use FFTW_MEASURE when planning) I think the benchmarks will be a lot more 1:1