I have set an AVX512 offset of 4, and the all core boost was 52x, that should give 4.8 GHz during AVX512.Just want to confirm the score you posted was using AVX512 at 4.8 effective clock?
Two cores have a maximum multiplier of 54x, so they might run at 50x in AVX512?
I haven't really tested AVX512 offset extensively, I just set the offset to prevent an instant shutdown if I end up running programs with AVX512 (and it actually works, I can run Linpack just fine)
I don't think Handbrake's H.265 encoder makes use of AVX512, HWiNFO reported all cores to run at 5.2 GHz pretty much all the time during the run as you can see.
Those 346W are just for the CPU die, there's a decent amount of power lost in the power plane, LGA1200 socket, and VRM at 200A current draw. Even in a high-end board like the Maximus XIII Heroand using 346W at the socket!