Sudden fps loss since the last patch?

6.21 came around, and I've lost a ton of fps. I used to be able to play at very high with 100+ fps, but now it lags at medium with 20 fps. The menus and stuff in the client seem to be laggy as well, not just in game. League is the only thing with new performance issues, so I doubt that it's my computer having an issue. I already ran a repair but that didn't fix it.