Of course I know that all games will take a performance hit when you tripple the resolution, but hear me out...
I'm using 2 x 5870 and they work just fine. In NFS Shift with 5760x1080 and no AA, I get about about 35-40 fps. Crossfire works but at the most both cards are only utilized about 75 %. If I switch to windowed mode with otherwise the exact same settings, I get 65-70 fps. And crossfire is not being used in windowed mode, so this is with just one card with 99-100 % utilization.
I'm puzzeled by a couple of things.
[list]
[*]CrossFireX isn't used in windowed mode, but I guess there are reasons for this.[/*:m]
[*]Why aren't more than 75 % of my cards' resourses being utilized when cfx is active?[/*:m]
[*]Why does one card at 100 % perform better than two cards at 75 %?[/*:m]
[*]Also, why is the CrossFireX-logo so big? In single monitor gaming, it's regular sized. (see image below)[/*:m][/list:u]
Btw, the image is from Dirt 2. Cfx works fine here and both cards are being fully utilized. I went into windowed mode by pressing Alt+Enter and then I maximized the window, but the performance hit was so big I didn't even bother trying to start a race.
I appreciate any input.
Edit: I just tested something I should have thought of earlier... I disabled crossfire in CCC and ran the game again. Same story. About double the framerate with just one card. This was in fullscreen mode btw. I also tried 3240x1920 portrait, but cfx doesn't even work in this mode. Still, framerate was about the same as in landscape single gpu. Oh, and I neglected to mention that I'm using Cat 10.8.
Edit again: Ok, so the problem seems to be that there is no CrossFireX profile for Shift. I renamed shift.exe to grid.exe and my framerate went up from around 40 to around 120 (although with a lot of flickering in the menu).