Just wanna chime in here and say my drive has been getting decent / advertised speeds at about 30% capacity.
X570 board, ryzen 3600 FWIW
However, today I updated from the 11.1 firmware to the 11.3 firmware, and now in crystaldiskmark my WRITE speeds for 4KiB went from ~500MB/s to ~350MB/s. This is a 30% reduction in speed!
It did not affect any other of the benchmarks in the test; however, I cannot get it to go above ~350MB/s in that test no matter how many restarts I do, benchmarks I perform, etc. It's not throttling either--Tmax for me on the mp600 is 48C
Cliffs
-the 11.3 firmware update may actually slow your drive down
-get it together please Corsair