DX11 Very High @ 1680 on 2x5870 runs at a bulletproof 60 fps for me; 1080p would not have been a problem but I figured beforehand that such a short game wouldn't be worth the lugging of everything to the TV. Might do so for any second playthrough actually...Found it:
http://forums.overclockers.co.uk/showthread.php?t=18133499
anyone else having similiar problems?
As for that dude, he has Advanced (Nvidia GPU) PhysX and tesselation turned on, options that together will shred his performance to bits. Bear in mind that to run GPU PhysX with an ATi card as primary requires a hacked driver set and some prayer; impossible to know (without him testing and telling us) if his 9600gt was being used and even if it was, it's still going to devour performance for very little gain.
Will the 480 play games like metro 2033 (and by implication other simiar future games) better?
A single 480 would also choke with those particular options enabled. Allow for a 50% higher minimum and you'd still be looking at a whole 22 fps.
As for other recent DX11 games, 5870 is faster than GTX 480 in Bad Company 2 and by a surprisingly large margin. 62fps plays 49fps at 1920 res.