When gaming (particularly PUBG), I get severely erratic GPU usage percentage which I believe is causing stuttering and FPS drops. Temperatures are excellent and CPU usage approaches but doesn't hit 100%. This doesn't occur during Furmark CPU + GPU stress testing (which is far more demanding) Any idea what's causing this?
System:
Intel i5-750 OC @ 3.6
16gb DDR3 RAM
AMD RX 480 4GB with latest 18.2.2 drivers
Gigabyte GA-P55-UD3R with latest bios
During gaming:

During Furmark's simultaneous CPU & GPU stress testing:
