Actually, core 2 quad will bottleneck the 650ti but not by much I suppose. OC the cpu will minimize it though
I have a Q8300 at 3.1GHz before and ran it with a GTX460. Games like Assassin's Creed Revelation, Dirt 2 & 3, Starcraft II and the Sims 3 all ran at 40fps or so on average. Minimums are borderline 30fps on most games (AC Revelation 20fps, Dirt 2 & 3 above 40fps). Switching to a 3570K showed huge improvements. Most games run at average 60fps and minimums are around 40fps.