Does my cpu need to be over clocked

I have just built my new pc -

i have 3 1080p monitors with 60 refresh that are run by the 2 gtx 680's now when playing some games i have experienced that the gpu's are at 75 - 80 % usage but i will get less then 60 fps, i am wondering if my processor is too slow for the level of grapics being processed -
maybe i should have got the k version and over clocked to 4.5 or somthing like that. at this point i have spent lots on this rig and i may have taken a hit by not getting the k verison of the cpu ... not sure what i was thinking. any thoughts or experiences would be greatly appreciated.





cpu-I 7 3770
Motherboard - asus z77 sabertooth
Cpu cooler - watercooled Kuhler h20 920
ram - 16 g x 1600mhz
power slupply - seasonic 860 platinum
video - gtx 680 x 2 (sli)
sdd - intel 120g (operating system)
hdd1- 500 seagate blue ( games and stuff)
hdd2 - 2 tb western digital (movies)
Case- nzxt - SWITCH 810 gunmetal