[seminatl]

None of your statements are correct.

1) Intel has per-core frequency and voltage control. To the extent that AVX-512 inhibits higher clock speeds that effect is local to the core or cores on which AVX-512 is active, and only those cores.

2) Not all AVX-512 instructions have this effect. `vpermb` for example does not.

3) Some other AVX instructions that are not AVX-512 have this effect. Also anything else that makes a core hot has this effect.

4) Most importantly, Cannon Lake microarch and later don't have this effect.