Use second port as an accessory display?

[dawmdt]

I am currently using 3 x 780ti on 3 monitors. Each monitor is cabled to one of the graphics cards via DVI. During normal extended desktop use, all is fine. During Nvidia surround usage, all is fine. My issue is with SLI - only the main centre screen (plugged into the first card) remains active meaning I have no separate desktop screen.

My idea was to put another cable from the second DVI port on the first card into the second DVI port on one of my monitors and then during normal or surround use deactivate (what Windows sees as) this fourth screen. When wanting to use SLI, I can deactivate the screen normally used in that position, activate the "fourth monitor" and that should suddenly work as an accessory display? Will this idea work or will the Nvidia cards/drivers or Windows suddenly get themselves in a confused mess?

 

[theadler]

Why don't you just connect all three monitors to your 1st card and leave in SLI? Only the first card will work in SLI mode, no matter what you do. You can connect 4 monitors to that first card and if you have to, use adapters such as hdmi to DVI.

 

[dawmdt]

Wouldn't this prevent Surround working though? Nvidia's documentation for Surround for 3-SLI is one monitor per card on the same plug type.

 

[theadler]

All GeForce 600 and newer cards support surround on one card with an accessory screen, 4 total, as long as there are as many ports on the card.
http://nvidia.custhelp.com/app/answers/detail/a_id/3119/kw/surround/session/L3RpbWUvMTM5ODQ3MTMzNS9zaWQveHhOR1hJU2w%3D
http://www.geforce.com/whats-new/guides/how-to-correctly-configure-geforce-gtx-680-surround#1
Yes you do have to use the same plug type for the surround monitors, you just have to get adapters so that all three will match.

 

[dawmdt]

That didn't work for me - I connected all three to the first GPU (using 2 x DVI and 1 x DP) and now 3-SLI works as desired (ie with an accessory screen when using SLI mode) but Surround mode no longer works - when I try to activate it the Nvidia control panel tells me I need to connect two monitors to the 2nd and 3rd GPU.

Indeed the second link you posted says exactly that (for 3-SLI) - one monitor per GPU for Surround, connected to the same plug on each GPU. The first link just talks about how to add a fourth accessory display to an existing Surround setup which is basically plug it in anywhere - this brings me back to my original question about using an alternative port as I don't really want to get a fourth screen...

 

[theadler]

Ok, well, your idea should work. Why don't you try it? Seems to me to be the best way to find out if it will work or not.