I give up... Lol
Like i said in my previous post that my old Q6600 @ 3.2GHz bottlenecked my GTX560. But then again it all depends on which games are played. Due to some being CPU intensive and others being GPU intensive. Others like a balance. Its down to the game really.
Now considering you can only run a Core 2 Duo you a limited by the all important older architecture and of course two less physical cores (not that many games use more than two cores even these days) but it is older tech.
I'd have to say at this point, go with what you have. Even get that GTX650 if you want because of course there is no doubt that it'll work and you'll be able to use it in a better/upgraded system later down the line.