Originally Posted by lapino
Do I 'need' it? Not sure. All games I currently have run pretty fine at 1920x1200 (sometimes without AA though). But I know I won't be happy with 20fps in Crysis2 or the new Witcher game. Any idea if there are even faster cards expected in the same price range within this and six months?
Really can't say about 6 months out.
Right now, no one knows about performance in Crysis 2, maxed out, so that will be pure speculation. I would probably recommend a card with more VRAM though (so the AMD card would probably be better suited). BUT, there are likely going to be new cards coming out, refreshed, which should provide decent graphics power in the next 6 months as the current gen is refreshed. You might get better "value" at that time and, to your advantage, you will be able to see benchmarks as well
Essentially, from a performance stand-point, the GTX 570 is probably going to be the better buy for you. If you want close-performance but also want to eliminate any issues with running out of VRAM, the 6950 would be fine (honestly, this should not even be a consideration for most games around 1080P and below). Either way, you can't go wrong.
Given that you have a 5850, it might not be worth a change right now. I'd suggest saving your pennies and going with whatever mid/high range card Nvidia and AMD release in 6-7 months time. You'd have a much better handle on things and the price/performance is only going to get better. Your current card should be more than adequate to tide you over till then