I want change my GPU. Today, my PC:
Phenon 2 X4 955 @ 3.7gh
HD 5850 Asus DirectCU
3 small screens: 19" + 20" + 19" - Total resolution: 3480x900
I play iRacing, Race07, GTR 2, Netkar PRO and rFactor without problems. Always whit 60-120 fps.
But, to run pCars - www.wmdportal.com - (High-Ultra) I only can use one screen to have a "good" performance. This way, I can run whit 28fps.
A Evga GTX 670 FTW 2GB can provide me a really good performance? Remember, my total resolution is 3480x900, substantially equal a 2560x1600 if we will think in a pixel quantity. I only plays racing games in triple screen. For games like BF3 I play with 1 screen.
I chose this GPU because my Scout Storm Case have only 10,5" (26,6cm) of space for GPUs.
"All displays must have a common resolution, refresh rate, and sync polarity"
So if they have all common specs it "Should" work.
Also this is something to think about. "* Supports all connector types. You must use three all digital (DVI, HDMI) connectors or three analog (VGA). You cannot mix and match digital and analog connectors."
BUT, AMD Eyefinity is MUCH more flexible in that regard, so it will work with an AMD card. I would suggest a 7970, 7950 or 7870 (whichever fits within your budget). They will all suit you perfectly and you'll be able to run anything maxed out with a 7970.