I went from a 7700K on my last game PC to a 9900K on my new game PC and the difference is very apparent in the game even though I had my 7700K overclocked to 4.5 GHz.

The difference is all the z390 board manufactures auto overclock straight from the factory with MCE (Multi-Core Enhancement) so the lowest the 9900K goes is 4.7 GHz (24/7) when under load and boost up to 5.0 GHz when needed with 2 cores.

The only way you can get all the z390 motherboards to drop to Intel's normal Turbo boost of 100 seconds max per core (with 3.6 GHZ base versus 4.7 GHz base) is by turning OFF the MCE, with makes little sense since it's really nice to have all the extra power without using any more Vcore than the 7700K uses normally too (1.200 V).

This is why the 9900K is so much nicer than my old OC'ed 7700K CPU.



CPU = i9 11900K
GPU = RTX 3080 Ti
Monitor = ASUS ROG Swift PG32UQX 2160p G-sync