Sudden fps drop in V8.2

So ever sense I downloaded the new patch every time i look at an enemy champ my fps drops by like 20-100 fps and that reallt hurts when your in a fight. I know its not my computer because I just upgraded my computer and the frame rate of my game is normal around 120-150 But what has upset me the most is sometimes when this happen everything will just freeze 30-60 seconds and ill be in fountain but this only has happend to me late game right before a team fight and i have lost 3 ranked games in a row because of this I just want to know if i am the only one having this problem I have tried changing my game quality and while ya ill get even higher fps but the freezing and drops still happen This only started this patch so ya