Cool, I am curious. The CoolerMaster MasterLiquid PL360 FLUX AIOs that I'm using on my 5800X3Ds do a pretty good job, they don't normally go above 65c and fans are usually around 70% percent then, but I've noticed when playing the Dead Space remake last weekend, CPU usage at 4K 100 Hz (CRG9) / 120 Hz (C2) was at a near constant 40-60%, ~60c, and those AIOs were working a bit harder. Still did great but I am curious about a 420 for 'em. Capping everything to 60 FPS tamed everything nicely but it was interesting watching the workout when going from 70-117 FPS in 4K.