I recently built a half decent PC for home use, media centre and programming. It's based around an AMD Quad Core Phenom. I put a nice 700w power supply in it, 4 gigs of ram and a couple terabytes of disk space. I don't game often so I didn't bother with a graphics card. Recently, I bought starcraft 2 thinking I could while away a few hours with it on my Thinkpad T61p. That doesn't work. the game runs for 10 minutes before the NVidia quadro overheats and the laptop shuts itself down to prevent damage. So I installed it on the PC and it runs but the graphics can get choppy and gameplay is a little slow and jerky. Also, I don't get to use a decent resolution or the game slows right down.
So with a budget of £100 to £200, what should I look for in a graphics card. I know very little about this subject. I currently have one 24 inch display and might add another. I want Starcraft 2 to work the way it's supposed to but I probably won't do a whole lot more gaming than that. If I get a decent card, my son might make use of it for warcraft and stuff like that.
I have seen a XFX HD 6870 for £200 that looks nice and seems to tick all the boxes but I wonder if there are comparably priced NVidia cards that I should look at too. Maybe the Gigabyte GTX 460?