Theoretical Question about GPU bottlenecks

[Dwardu]

Hypothetical situation...

Lets say, I had a PC with an Intel Celeron Dual Core and a GTX 660
I am capped in <some game> at 30 fps because CPU is slow and cant utilize my 660 entirely

Instead of upgrading my CPU as I should, I upgrade my video card
What happens? Will my game perform better, worse or exactly the same?

Please do not tell me "This is stupid." because I am fully aware of this. I'm just curious, in theory, what would happen.

 

[Willdobbo]

It will perform the same as it will still be getting bottlenecked by your cpu.

 

[Novuake]

Its not quite that simple since every game will change this. But in short Willdobbo is correct.