@ Pandacoot: You do n't specify the monitor resolution...Hint.
The 7950 is a monster card, I've just added one to my i5 750 build as its mid life upgrade, but a few points to bear in mind.
First, make sure the powersupply has the right PCI-E leads to power it, you should NOT use molex/PCI-E converters to run such a card.
It can produce a fair amount of heat, and most of the cards out there dump their heat into the case, so good ventilation is also a must.
As Ohmybad says, the i5 is a better gaming chip.
Do n't forget to add a decent cooler into the mix and go for a 'K' chip so you can overclock later to unleash more performance.
Thanks for the replies. I'm a bit new to all of this, as is probably obvious. My resolution is 1920x1080.
Cool, I'll look in to i5's instead of i7's in the future. That'll save me a bit of dough.
As for my PSU, I've got a pretty beefy 600W OCZ, so I don't think power will be a big issue. My rig also runs relatively cool as of now and I've got solid ventilation, so I don't think that should be a problem either. Mostly I'm just looking for the highest performance, and it looks like both of you recommend upgrading my GPU first and then upgrading to an i5 in the near-ish future. There's no chance of my i3 bottlenecking the 7950 in a serious way, though, is there?
Get a i5 3570k with Radeon 7950. i7 are more for rendering, encoding and other stuuf which professionals do. i5 is for gaming, i5 3570k and i7 3770k are similar to each other in games.
i3 would not bottleneck but would lower your performance in multiplayer matches. Online matches like the 32 & 64 Players matches of BF3 will run slow on Dual Core i3 and would be good if you get a i5 Quad Core processor.
You'll get a very significant improvement jumping from a 550 to a 7950.
As has been said already, the CPU is going to a restriction, but it's not too bad, the i3s' can get very close to i5s' in many games, it's only in those few that really use multiple cores (like BF3) that it will hurt.