LOW FPS HIGH END COMPUTER 24fps average

So I have a high end computer. Now for the last month I have not been able to play league at all. I used to run the game on the highest settings with over 140fps. Recently regardless of the settings in game, i never see above 24fps. All drivers are updated. I have followed all the support links, ran all the diagnostic checks, and can run every other game on max settings. I even have uninstalled and reinstalled the game multiple times. Fallout 4 max graphics=perfect ARK=Perfect Forza Horizon 4 max=perfect