I started to play GTA V with some friends last night and I noticed around 17 fps on old settings I used to run at ~45-~60 FPS and now I have messed with the nvidia control panel trying to fix things but were still running low core speeds while at 99% load.
535MHz on the core
810MHz on the memory
No Overlclocks
Default Bios from Gigabyte (Vendor)
99% Load
Power Limit priority at 100% (not sure if important)
P.S. Not sure if any fixes but I am getting a SSD for Christmas so I was going to reinstall Windows, so this could be a broken installation but probably not and just reinstalling everything should fix but rather fix it in one day then reinstall windows twice in like a week.