– Upgrade from B450 to B550 motherboard resulted in unstable 4000Mhz Sk Hynix kit which was working fine on B450
– 3800Mhz did not post at all, no matter what I tried
– So I decided to plug in my old 3200Mhz CL16 Samsung kit to get rank/capacity benefit
– 2x1R 32GB 4000Mhz CL18 -> 4x1R 48GB 3200Mhz CL16
– Training was not easy, especially at these voltages. But Memtest86 1 pass done, no errors
– 23.01W package power draw at idle, 99W absolute max. Scythe Fuma 2 cooler fixed at 364RPM with indefinite all core %100 stress at +200Mhz PBO. Very happy
– 2298/10282 geekbench score on linux (compared to 2x1R 4000mhz CL18, that's ~7% better multicore score)