A Look At The GCC Compiler Tuning Performance Impact For Intel Ice Lake

FFTW did see a fairly noticeable gain when AVX-512 was flipped on with Skylake-AVX512 but the extra instructions (and different tuning / costs tables) for Ice Lake client hadn't yielded too much of an uplift -- but the benchmark did come out slightly ahead of the -march=skylake-avx512 result.

With a larger sequence, skylake-avx512 had regressed the performance but the icelake-client tuning did help it recover to basically Skylake levels.

But in the case of the MrBayes scientific workload, the skylake-avx512/icelake-client builds did slowdown the performance, potentially due to the lower clock speeds of AVX-512 usage.

QMCPACK meanwhile did perform its best with the icelake-client tuning.

HMMer meanwhile was another workload that slowed down with the AVX-512 options.