It´s quite possible that
1. Either your hardware CPU, GPU or RAM is failing
2. You have high temperatures causing your CPU to throttle
Its likely that it's the 2nd possibility. But we need more information.
Taking Dolphin games and those PC games you mentioned, do both of them just freeze every few minutes but stay playable? Or do you crash? (Blackscreen, BSOD, audio loops, display turns off)
It can't hurt to monitor your temps already either. Get a temperature monitoring application such as CoreTemp and check what your temperatures are on idle and when playing your games.
1. Either your hardware CPU, GPU or RAM is failing
2. You have high temperatures causing your CPU to throttle
Its likely that it's the 2nd possibility. But we need more information.
Taking Dolphin games and those PC games you mentioned, do both of them just freeze every few minutes but stay playable? Or do you crash? (Blackscreen, BSOD, audio loops, display turns off)
It can't hurt to monitor your temps already either. Get a temperature monitoring application such as CoreTemp and check what your temperatures are on idle and when playing your games.