I've put 85 hours into this game (partway through my first playthrough) and all of a sudden the game runs at 15fps. Normally I'm between 50-55fps with near everything on Ultra and hairworks on Geralt.

i7-4790k
MSI GTX 970
16GB RAM

Last night I did a clean install of graphics drivers because I was having issues with the Nvidia control panel. Install went great, cleaned up my PC, and played the game for around 2 hours after that. No issues, no crashes, continued great performance. Booted up the game this morning and it is stuck at 15fps. According to MSI Afterburner my GPU usage is at 100%. I'm at a loss for this one. Anyone experience something similar? I'm stumped.

I know it sounds like a simple thing, but try rebooting again. If that doesn't help, roll back your graphic drivers. I recommend giving the nVidia iCafe drivers a try. They work wonderfully for me.

3rd reboot didn't do it, unfortunately. Always worth a try.

I can't roll back because I just did a completely clean install, but I'm willing to try another clean install. Having said that, I did some more benchmarking and for some reason my GPU says it's at 100% usage, but only 20% power. I have no idea what's going on there. I'd assume that isn't driver related? Could be wrong though.

Because this will be someone's next question I'm using a 4 month old Corsair CX750.

EDIT: I've got some kind of system issue. Not the game's fault (probably). Guess posters can disregard this. Though if anyone has insight as to what might be causing this power issue it'd be mighty appreciated.

No, sorry, it's running at 20% power during games/benchmarking. It's bottlenecked for some reason. It's indicating 100% usage while playing/benchmarking but only 20% power, which I assume means it's running as fast as it can on only 20% power.

Thought RTSS was acting up so I deleted it, but that did nothing. It's certainly not an issue exclusive to W3 now, and I realized it happened mid use this morning becuase I played another game with it functioning perfectly before booting up W3.

EDIT: One of their hotfix drivers fixed the issue. Weirdest thing I've ever experienced. Power bottlebeck because of a driver. Whatever. It's working again.

Drivers was in my very first post. ;p

I know, I just couldn't roll back so I was saving it for last. I was loathe to believe it after a clean install :( Could also be something to do with driver interaction with Windows 10. Who knows. Just glad it's working.