Some things I've noticed are the gpu used to run at 99-98% usage the moment I was in the game, but after I disabled the gpu in device manager -> restart -> re-enable gpu => restart, it now runs at 60 - 80 %. I've attempted underclocking, reinstalling drivers (DDU in safe mode and reinstalling), w/ and w/o mods, reinstalling game, verifying game cache, etc. Sometimes it crashes almost immediately upon the game loading in.
I've been trying to play the witcher 3 on my new rig but have been unable to get the game to play longer than an hour, and usually any longer than 5 minutes. I haven't tried witcher 3 with my old 970 yet. Although, since I built the rig I've only played B元, witcher 1 & 2, and Doom 2016.
I do NOT have this issue in any other game that I've seen. UPDATE: I had a little more success with removing AA but unfortunately I ended up refunding the card and now run a 2070 Super without issue.