I'm running a 6970 ( specs below) with RoF @ 1920 x 1080 , 8xAF, 2xAA, and supersampling.
I also have bloom and other effects. I can run HDR without problem but I don't particularly like the effect.
Haven't had an issue. Hope that helps. I went with the HIS card which I believe is a reference design card.
Edit #2: I started a thread in which I described my "tweaking" experience for this card, the above are the max settings I was able to squeeze out without any impact on performace. The card can do 8xAF,
4xAA, and supersampling but it some stutters with overcast skies. I never OC'd the card.
Also, you should have a full tower ATX case (I have the CM 690) as these cards take up a lot of space... though you probably realize this, I just thought I'd mention it.
Good luck
