Which upgrade will work better? [CPU/GPU]


Dec 14, 2012
Hello guys.
I'm new on this forums, and I wasn't quite sure which category for my problem would be best, so please forgive me if this one is wrong.

I am in the middle of upgrading my old PC but it's one step at a time. So far I've changed my MOBO, CPU, HDD and RAM and at this point it looks like this:

Power Supply: 430W HIPRO
MOBO: Gigabyte B75M-D3H [I think it's quite good and will allow me to do some upgrades that I need in future]
RAM: 8GB @ 1600
HDD: 2TB @ 7200 @ 64MB cache
CPU: Intel G840 @ 2.8GHz (it's 2 cpu)[\b] - it was the best performance for money choice since my old CPU broke down lol. - it is gonna be changed.
GPU: GF 8800 GTX

So at this point I aim to either upgrade my GPU along with the Power Supply OR the CPU.
The question is:
Which upgrade will be better for gaming, which upgrade will affect the overall performance more? At this config I can run FarCry 3 in "medium" and it is playable.

I know that my GPU is quite old, but in some benchmarks it's actually not that bad compared to modern ones. In terms of GPU my budget is $280 MAX (around) but I would like to spend less. I've done my homework and somewhat in this range there are GF 650Ti, GF 560 TI, Radeon 7850 - I THINK, maybe there are other better ones that you could suggest in this price range that I missed.

as for CPU my budget is slightly different, I would aim for quad core i5 or i7. so it's around 300 bucks, maybe a bit more. but around that.


So again, which upgrade (CPU or GPU) that I suggested would affect more the overall gaming performance of my machine?
I think the GPU (as my CPU is theoreticaly the same as i3), but please tell me your opinion and make some suggestions :)