Help setting up CRU with 390hz on AMD 6650 XT

[ToastyX]

What you're doing should work. Does Windows not list the refresh rate in the advanced display settings? That would mean the driver is rejecting it for some reason. I can only think of two things. First, leave the DisplayID extension block as the second extension block. That shouldn't matter, but you don't need to move it. Second, the blanking might be too low. It looks like you're using "Exact reduced" but that might be too low for AMD at these higher refresh rates. Try copying the timing parameters for 360 Hz.