Wondering if anyone can give me a hand. My specs are as follows:
CPU: 2500k @ 4.5Ghz
Mobo: p8p67 pro asus
GPUS: 2x 5970
PSU: 1300Watt Tagan
Ram: 8GB 1600Mhz
I recently purchased the second 5970 to increase the longevity of my pc, since I play at 2560x1600 I can't really keep up without having the latest and greatest.
Anyway I've been banging my head against a wall ever since I got the second card.
First I was BSODing non stop on every driver i was trying. Then with a BIOS update to the mobo I finally managed to make things work though I cannot run individual monitors off each card at the same time (Gaming on one stream/vid on the other) without BSODing.
Eventually I managed to make things sort of work-ish in games by eventually settling on 12.1 and 12.7 CAP 1.
I'm still experiencing occasional jittering and slow downs every 30 seconds or so while playing BF3 particularly on the bigger maps. Initially I believed this to be the high settings and only having 1gb available ram amongst the gpus but lowering the texture/effect settings down to high instead of ultra doesnt really seem to help.
I've got no AA on, textures and decoration on medium, the rest on ultra.
Thank you both for your very helpful and informative replies - fantastic actually.
I actually have some interesting results; I realised before reading the first post that my pcie lanes weren't running correctly and changed that in bios which seemed to help the BSOD/freezing troubles.
Powering back up bf3 I noticed significantly better fps, though there was very wide variation (jumping from 50 to 150fps looking at the same scene) with mostly everything maxed out at ultra except for the MSAA and Texture/Decoration stuff (Vram being the limiting factor at 2560x1600).
Anyway I alt-tabbed to see that my cpu was still being maxed out (4.3GHz 2500k!) and the gpu util was less than 50% so i upped the volts to 1.35v on vcore and bumped the speed up to 4.7Ghz (though my temps held up with my H60). This gained me SIGNIFICANT increases in performance now it's running steady over 70fps (sometimes as high as 150) with all the bells and whistles on (vram permitting ofc) and yet the gpu util is still around the 75-80% mark whilst maxing out the cpu (at 4.7GHz!!!!!!).
Long story short: i5 2500k bottlenecks a pair of 5970s in crossfire at 4.7Ghz... utter madness!