after searching I have not found a solution.
I have 2 nvidia quadro 295 cards with 3 monitors but I can not extend twinview across multiple GPUs.
I have the most recent nvidia proprietary drivers installed, and they work fine for the single GPU / dual monitors. I tried using xinerama, but without success.
I don't mind switching to the nouveau drivers if that would handle my multiple monitors, although I would like to continue to use unity and compiz if i can).
it turns out that Unity and Xinerama do not play nice together anymore, as Xinerama and Composition cannot be run simultaneously. until rrandr takes over multi-gpu stuff, or until twinview gets much smarter, multi-gpus will not be possible for most newer window managers (Gnome3 suffers from this same problem).
i tried backing down to ubuntu classic to get it to work, but i'm tired of screwing with it. it would replicate the same screen on all 3 screens, but wouldn't treat them as one big one. sadly, there's no real great examples of how to get this to work in xorg.conf.
so for anyone else trying this, you're pushing a rope in respect to Unity/Compiz. you can probably get it to work in Ubuntu Classic, but be prepared for a fight.
this is pretty sad. if i could get Windows 7 running on this box, i'd use it and run linux in a VM. that's what people are going to have to do to get this stuff running on multi-GPU systems.
i was able to get this working thanks to a coworker. here is my xorg.conf file. this required gnome2 and the proprietary nvidia drivers.
I have 4 screens hooked up to 2 identical Nvidia GPUs
In 10.04, I had it working flawlessly with Xinerama. But, after upgrading to 12.04, everything is screwed up. I installed GNOME shell cause I hate Unity. I use GNOME classic.
The closest I can get to working is TwinView and 2 X sessions but GPU2 shows a white desktop background, as soon as I enable Xinerama everything breaks and I have to start from scratch again.
Also depending on Ubuntu/Nvidia's mood
nvidia-setting
will sometimes show only 1 GPU. Other times I get both and can continue with my setup.The one working copy of
xorg.conf
I used amv
command (instead ofcp
) on and lost my working backupI got all 4 working again and Xinerama.
Here is my xorg.conf:
Nvidia have implemented a solution named Mosaic. Mosaic can work over SLI, or on SLI capable cards that aren't SLI connected. These are known as SLI Mosaic and Base Mosaic in that order. You can search for
Option BaseMosaic
to find doc, caveats etc.I get to be a lucky person whose cards are "not approved for SLI". Thanks Nvidia for making Linux users second class citizens - Windows works just fine on the same hardware - and it is a lovely reward for buying two of your cards!
Have you tried just running
by any chance?
I usually find that if I can't sort out what I need manually with nvidia cards and the proprietary drivers that just running that usually sorts everything out I need. I just need to sometimes change the order of the monitors later is all.