Hi i would like to know if possible to add an entry to the grub menu (and where) to select a different xorg.conf file. I have a GTX295 card and dual monitors for desktop but when I want to play games I would like to boot only into one monitor with SLI enabled (cant enable SLI with dual monitors)
Well, Failsafe/Recovery mode uses the “x11failsafe” boot option, which forces X to use /etc/X11/xorg.conf.install as configuration.
So you could “misuse” this for what you want to achieve.
Otherwise you would have to change /etc/init.d/xdm (or create a new init script) to respect another boot option and pass a different config file to Xorg, I suppose.
Just an idea.
I don’t have neither an nvidia card nor a dual monitor setup. Maybe there’s some better way to achieve this? (with nvidia-settings f.e.)
Thanks wolfi323 Will look into that 
Well it seams I have both cards working with dual screens ? I made changes to my xorg.conf file and added
Option "SLI" "Mosaic"
Option "MultiGPU" "AUTO"
Option "BaseMosaic" "On"
I have nvidia settings running while playing games to check and no both GPU’s are showing they are being used and the memory as well.