I have a i7 4790k stock cooler, 8GB G.Skill Ripjaws X@1600, MSI Z97 Gaming 7 mobo, EVGA 750w PSU and a pitiful Radeon HD 5770 GPU running on Windows 8.1. I have used this rig for 6 months now and suddenly I lose half my framerate after 15 mins of gaming. This happens in all games. My rig is not dusty, my drivers are up to date and I have run Malwarebytes. My CPU temp is 60-65c in game and I have seen it crush video production at 80+c for 15 min with no problems and benchmarked with Intel XTU to the tune of 100+c before thermal throttling kicked in, so I feel like 60-65c temps are not an issue here. The FPS drop does not seem to be linked to GPU either, I can overclock my GPU a tiny bit with CCC and it seems to give me a few extra FPS when OC'd a few less with stock settings, but I get this huge FPS drop in say: Pillars of Eternity, while standing around doing literally nothing after 15 mins or so. Restarting the game does not help. I must restart my PC to get my 60+FPS back in any game, which holds solid for 15 mins or so until it goes back to 30FPS or less. Any ideas? I get my GPU is old but these games run screaming fast for long enough before stopping I have a hard time thinking a GPU upgrade is the only fix. I am worried about the health of my PC.