Currently i have an intel i52500k overclocked to 4.5 ghz. It is paired with and nvidia 660ti. I have a little cash to burn, would it be worthwhile to upgrade to an i7 3770k or upgrade the gpu to a 770. This is for fsx.

 

I'm guessing 10% increase in performance, perhaps 15% dependant on the scenario. It's a guess though, all systems are unique. Increased smoothness is another question, case of suck it and see. Higher AA may be possible.