FPS question, im about to replace my GPU, need help.

[Kizax]

So i'm gonna replace my gpu in about 7 days, with EVGA GTX 780 superclocked.
The one i have now is GTS 450.
CPU: Q8300 3.5GHZ
my games work on 40-50FPS, are they going to be better with EVGA's gpu or same cuz of my CPU?

 

[Kizax]

Oh, forgot to mention, the card is actually a gift..so i cant choose.