so i have a radeon HD 7850 2gb and recently i bought another one for $140 1gb with 2 freegames(Bioshock and Tombraider) a week ago and my new PSU is on the way, however my current PSU is 500w, the one i ordered is 600w; so today i plugged my new Card and tried crossfiring, but it seems that any game i play i experience stuttering all over. is it my PSU or or there is something wrong with corssfiring or is it because one of my GPUs is 2gb while the other is 1gb? or my PSU isn't capable of handing both?
CPU: intel i5 2500k 4.2
GPU 1: Sapphire Radeon hd 7850 OC version 2gb
GPU 2: XFX 7850 1gb
Mobo: Asrock Z77 Pro 4
RAM: Kingston Hyperx BLu 8gb
HDD: Western digital caviar black 1tb
SSD 1: Samsung 840 series 240gb for OS
SSD 2: OCZ agility 60GB
PSU: Coolermaster Extreme 500w
depending on the game it could be a ram limitation. games like BF3, Crysis2 and Skyrim all use more than 1gb vram at max settings. That WILL cause stuttering, especially when you add crossfire into the picture. the psu you have is not enough, but it may not be the issue causing your stuttering. Crossfire is crap at the best of times, particularly on mid range and low end cards. turn all the details down in your games and see if it still stutters, if it doesnt your probably maxing the vram of the 1gb card. If i were you i would sell both cards and get a better single card. You probably could get away with not upgrading the psu then, and you wouldnt be restricted to medium detail levels by your 1gb card.
there are 3 things on that page. the 1st item are the catalyst drivers, the 2nd is a beta driver, the 3rd is the caps ( for multi gpu setups.) you need catalyst AND caps for multi gpu setups (1st and third)