*Chuckle*, Justin you are using a Reaper evaluation license
Okay, fun aside...
@lucor, there's just something that came into my mind. Can you check, if your
CPU speed is changing (task manager), when Reaper is running?
Cubase has this power profile, that always sets all CPUs to full speed.
I could imagine, that your CPU is running at lower speed, unless you have turned off all the C-states (which I always do, when I get a new machine).