about what you said about not getting over 60 fps in League.
i had the same issue before, but after some researching i found out that since i have a 60hz/fps monitor and V-sync turned on. i will only get max 60 fps, since thats what my monitor is running.
if you either in-game turn of "wait for vertical syn" and/or turn of v-sync for that particular game in nvidia control panel you will get a lot more.
on my 60fps, 1080 monitor, with max settings in LoL i got around 300 fps.
so anyway, its the v-sync that is limiting it for 60 fps. (maybe its because you have one 60hz monitor in your setup (?) it measures how many fps you have on the "worst" monitor (aka the weakest link)
Let me know if that worked out for you.