Can you give a real example of AVX-512 actually causing a net performance penalty on any CPU? The only way I can see that happening is using AVX-512 in small,

Can you give a real example of AVX-512 actually causing a net performance penalty on any CPU? The only way I can see that happening is using AVX-512 in small, infrequently called functions such as strcmp, and the solution is: don't do that. If proper SIMD code runs for say 1ms at a time, it's pretty much guaranteed to benefit from any implementation of AVX-512.