Should I Upgrade my Cpu or Gpu

I got 200 bucks to spend on an upgrade but i don't know what I should upgrade first. I'm eventually going to upgrade everything to the point where I have a new build but I can only do a little at a time. So currently i'm running an radeon hd 4550 with a amd athlon 64 x2 4000+. Now I know full well regardless of which one I upgrade first i'm going to have an extremely severe bottleneck and ideally I would upgrade both at the same time but I can't so I got to do it this way. So should I get a 7950 or a 660 and and use that with my athlon 64 x2 4000+ or should I get a fx-6350 with a new motherboard and ram and just use the 4550. Really what I want to know is which one will give me the best increase in performance, which ones the lesser of two evils. Hope this was somewhat clear. I have a corsair TX650 so power isnt an issue or nothin. Any questions feel free to ask. Thanks

If you want to play games get a 7950, it is seriosly 20 times faster than the 4550. Sure, its only going to be at 50% load in many games but that is still 10 times faster than an extreme edition with a 4550.

Go for the 7950 first, chances are most the games will be GPU limited more than anything.

Like everyone else here I would recommend you go with the GPU. Spending money on this will give you much more performance then CPU. If you get the processor first you will have the extra power in other tasks but it wouldn't make as much difference in games. The added power of the CPU only really is harnessed once you start getting into GPUs such as the GTX780. Hope this was helpful.

If you want to see a bit of a comparison then check out this  video as the CPUs tested is a Athlon 750k vs an i5. https://www.youtube.com/watch?v=qIT9uLDjZcg  

Yeah, I agree with the rest of the guys.  HD 7950 first.  Then focus on upgrading your CPU.