I have i7-2700k 3.5Gz + 8gig RAM. up until recently I had only 1 sapphire 6850, but then decided to buy a second and crossfire. i have made sure all my drivers are up to date, and installation went smooth, but the increase in performance I saw during games (Deus EX eyefinity, Skyrim 1080p, burnout paradise eyefinity) was only ~ 20%.
do you think this may be a bottleneck situation or do I have higher expectations than i ought for crossfire?
your cpu is too strong for gaming it is impossible to bottleneck even with hd 7970
crossfire but the only cards that make bottleneck when sli or crossfire is gtx 690
, gtx 590,hd6990,and hd7970 quad crossfire even with i7 3960x 4.7 . i think the source of problem is your driver as ati has worst scaling performance in the world
especially in Skyrim . second i dont think your hd 6850 crossfire isnt monster to run
those at 1080p i thing you have to buy gtx 680 or hd 7970 or gtx 670