For all the guys saying "windowed game" "autohotkey" ecc, i know exist, i use it. But still, the script for hiding boorders mean it's a fake fullscreen. It have the same performance of regular windowed mode. Try a game in true fullscreen and you'll see better performance. That's why alt+tab in fullscreen it's a welcome feature (and don't really open a window for botting since there's already windowed mode...)