Opinions on xfire 6850s, pls.

[upcoast604]

Specs in sig.
My big concerns are min fps drops, mobo pci e is only x8/x8 and over all stability?

Games that I'd use are Crysis, Crysis Warhead, Crysis 2, BF3 eventually, BFBC2, Fear3, Fear2, Farcry 2, NFS The Run/Hot Pursuit, dirt 2/3 , Black OPS and MOH.

Is the 1GB vram enough for each card at x4aa/x8af high quality 1920x1080?

Maybe I should xfire with a 6850/6870 incase it doesn't work out I could sell the 6850 and keep the 6870, I already have 1 6850?

Like I said opinions pls'n thanks.