Hello, this problem persists over multiple nvidia drivers, 319 and 331 for Ubuntu 13.10 for me.
NVIDIA 590 GTX x2 SLI (4 GPU’s recognized)
2 Monitors plugged in first Card/GPU, 3rd monitor plugged into 2nd card.
Screenshot of nvidia-settings: http://screencloud.net/v/sydo
I am unable to enable ANY of the SLI, MultiGPU or BaseMosaic Settings in xorg.conf or else the system will majorly slowdown as soon as I log in and the desktop starts to load.
By slowdown I mean the mouse becomes extremely slow to move, desktop never shows, and control-alt-f1 takes 30s-2 minutes to respond. Once TTY1 becomes active, that responds just fine.
I am trying to get Base Mosaic working specifically to get the third monitor working.
I did however try 12.04 (attempting to resolve another issue I have) and Base Mosaic works fine and all 3 monitors work! But 12.04 did not solve my other issue so there isn’t much point for me to reconfigure 12.04 back to a working condition when 14.04 is around the corner.
I am looking to hopefully get this working before 14.04 (and hoping 14.04 works too like 12.04).
Any advice would be appreciated.