Would a stock i3 520 (2.93 gHz) bottleneck a GTX 560 (NON Ti)

[dpk33]

overclocking isn't possible

 

[Necc]

In games that utilize 4 cores or heavy on the cpu i.e RTS, MMO's, GTAVI there will be a bottleneck, but if play GPU heavy games ie Crysis, Metor2033 then there wont be any noticible bottleneck, depends also on your resolution if your play at 1920+ with AA then GPU will be doing most of the work but cpu will still matter.

My brother PC which has my old E5200 with an HD5770 has like 30fps 1920x1200 in L4D2 when there is a zombie horde, but that is expected because L4D2 loves QuadCore's. so he's CPU bottlenecked.