demo
====
prime.offload:
iGPU: 220FPS
dGPU: starts above 200FPS but slows down to 77FPS
prime.sync:
dGPU: starts at 140FPS and slows down to 113FPS
or
dGPU: starts at ~300FPS and slows down to 188FPS
slowdown seems to be related to GPU thermal throttling reacting to increased CPU
temperatures