Mat just released a new Bootcamp GPU driver (Adrenalin 18.8.2). Unfortunately it only works for Vega 64. This driver has a massive drop in GPU temperature (20+ Celsius), which makes a big difference with fan noise. Link: http://bootcampdrivers.freeforums.net/thread/341/imac-adrenalin-dedicated-driver-alpha Edit: GPU core speed doesn't go past 1300-1310mhz in modern dx11 titles (it should be 1350mhz). So there's slightly less performance, but considerably less heat output. Not a bad trade-off.