3 monitors?

I am trying to set up my computer with 3 monitors, and what ever i try, i get one monitor with a black screen.

i have had all three monitors one either card, two on one and one on the other, and reversed. 

i know this should be possible, but i am really loosing my hair here (what i have left anyway) 

i have two geforce 580 gtx, i do have the SLI thing plugged in, but it is disabled. 

 

does anybody know what to do here ? 

Well. I would suggest that you turn on SLI.

Here is how: http://www.computerhope.com/issues/ch001167.htm

It is a little outdated, but it's so simple. The only thing that have changed, is the look if Nvidia controlpanel. 

i have now tried :

connecting all 3 monitors to both cards.

mixing it up, having 2 on one and 1 on the other, and the other way around.

having SLi disabled, "activate all displays" "span displays with suround" and "maximize 3D performance"

no matter what i try, one of the monitors stay black.

nvidia control panel tells me to try a different connecter on the same GPU (not sure if it means the one it is already on or on the same as the other) anyway, i have tried putting it on both, and still one black screen... 

i am almost ready to give up here... 

could it be that i am not able to use the same resolution on all three screens ?

what connectors are you using?

 

i have 1 on HDMI and 2 on DVI... i have tried having 2 on HDMI and 1 on DVI, the last one only have VGA and DVI

In the Nvidia control panel, Can it see all three screens? If not then one of your GPU's have a  faulty output, Try just using 2 screens and see if you can make one of them not work by just switching which ports you are using.

i can see all three monitors in the control panel, both nvidia and windows

OMG... i had no idea that the connecter on the cards made a difference, i must have used the same connecter on one of the cards, but anyway it works now... 

thanks to all of you, i has been a mix of everything i think...

i put the connecter in the other DVI on the first GPU and clicked on aktivate all displays, and i got a picture on all monitors... i cant belive it was that easy...