I can understand people not reading the docs, but from the docs page. Q: GameEx really uses a lot of the CPU, nearly or exactly 100% A: Set NoWaitSync= True and Sleep=15 in GameEx configuration under Tweaks/Performance. You may need to reduce the sleep setting on older PC's, or you can possibly increase on faster PC's. On an Athlon 3400 64, I can use these settings without any slow down. After running GameEx with these settings and looking at the Performance tab in Task Manager, GameEx was consistently using about 8% of the CPU while it had the focus. Note: In recent versions, mostly GameEx uses 0-1% CPU when it does not have the window focus, regardless of these settings. Basically by default GameEx uses the entire CPU power, but the sleep setting releases back cycles every frame. On the latest CPU's you can get it to run at about 5-10% and still smooth as silk