I'd go as far to say alot, looks like if you feel you need more performance you would be better off with going all out than crippling a new card with your weak processor. Also now that the 770 is out the 670 is obsolete.
I just realised that my CPU is overclocked to 2.8Ghz. Was just wondering if the bottleneck will still be as bad?
Also, I have a small budget, so I have to go for the cheaper Graphic Cards.