SLI 580 & tertiary GPU for extra screen

[CurseUppl]

Hello, been lurking here a while ever since I began deciding on what to put in my up and coming PC.

I've tried searching, but I can't seem to come up with the right combination of search strings that will not yield unrelated topics.

So, long story short, I'd like to know if it's possible to have 2 580's in SLI for *one* screen, (2560 x 1440) and then have an additional, cheaper GPU (I'm thinking a 450 or 460), not in SLI, to run my older 1920 x 1200 screen.

My planned build is this:
Asus Maximus IV Extreme-Z
Intel i7-2600K quadcore
16 GB 1866 MHz, dual channelled
2x MSI N580GTX Lightnings (I'm not 100%, though this model seems to have quite decent cooling)

Putting it all in the Lian Li PC-X2000F, so space really shouldn't be an issue.

Also, if you have any comments regarding the build, I'm open to suggestions.

Thanks a lot for any help.

 

[solomonshv]

not sure why you would want to do that. Those 580's have more then enough horse power to run an additional monitor. If you want it just to see your hardware status readouts or for chat clients while gaming, then you wont put a dent into the performance on your main screen.

You CAN have an additional card for that extra monitor, but when you go full screen on games like crysis 2 or starcraft 2, the second monitor will still go black even though it is running off of another GPU.