I have a similar question over on the GPU forum but thought I'd also try here.
Basically, my GTX 560ti is about to die, and also, it isnt giving me the performance it once did. I've always liked the '60 series' (I've had a 260, 460, 560 and now a 660ti..) but my question is...
Will I see my performance in games like Battlefield 3, Guild Wars 2, World of Tanks Online etc hampered by my CPU? I only have a core i5 760 @ 3.2ghz and, though I would love a SB chip, just can't afford it at the moment.
For now and with regard to graphical software, will I see a performance increase going from a 560ti to a 660ti, despite having an old(ish) cpu?
to find out if you are getting a bottleneck, use something like MSI afterburner to monitor your GPUs load while playing CPU intensive games like BF3. if the GPU is always around 90-100% load, there is no to very little bottleneck. if it's hanging around 70-80, you might want to upgrade in the near future. but i highly doubt there's any bottleneck at all. most people are still fine chugging along with decently clocked core 2 quads.