FPS so low for awhile but I decided to ask how to fix just now.

3-12 fps most of the time,REALLY hard to play when it's around the 3 fps mark.... I tried the alt+enter,and setting it to borderless,it's like this in both new and legacy clients so it's not the client (even though it's laggy in champ select for new client,but let's not get into that and confusing you guys) I guess it started around like....patch 6.22? 6.21? or something i don't remember that far back specifically. any fixes? I also notice there's multiple league of legends running in my task manager under the "processes" tab ever since they released the new client.