Triple Monitor? Nvidia SLI + Ubuntu 12.04 LTS

[destrekor]

So... yeah, this has been ugly. Triple screen simply does not want to play nice.

Does Gnome 3 (Shell) play nice with triple monitor? Perhaps it's simply Unity that is making this more painful than it ought to be?

I've got the latest Nvidia driver installed. No matter what I do, if I have three monitors enabled, I cannot get Unity 3D (or, that does not appear to be the case at least).

I should be using Xinerama, yes? I might be able to do TwinView + 1.

Ultimately, I'd love it to be like Windows' approach to triple monitors, at least, my typical configuration (three monitors, not one 5760x1080 monitor, which I only use for some gaming).
But Xinerama seems to make it one large monitor (ignoring Unity looking ugly and buggy with this enabled), and I'd really like to be able to have three monitors where I can just drag windows across them, with local maximized windows.

 

[destrekor]

Things *might* be coming around to how I want them.

After deleting xorg.conf, I ran:
sudo nvidia-xconfig --base-mosaic --metamodes="GPU-0.DFP-0: 1920x1080+0+0, GPU-0.DFP-2: 1920x1080+1920+0, GPU-1.DFP-0: 1920x1080+3840+0"

But I'm not entirely sure this is what I want, as it isn't what I was looking for in the end.
This results in one logical monitor (Screen0) with a 5760x1080 resolution. Yet, it's different than what I imagined for a monitor of that resolution. This isn't xinerama, which is nice. Windows don't maximize to the full resolution, instead they are local to each physical monitor. Even better, each monitor has local "snap" zones in Unity (and Unity 3D is still active!) that is like Windows. Except this is better than Windows "snap" with multi-monitor, as only the right-most-edge of the right monitor, and left-most-edge of the left monitor preserve that functionality with multi-monitor Windows 7.

But (perhaps this is Unity/Gnome-specific), the system bar (or whatever it's called) up top is duplicated on all three monitors, though that is better than it stretching across all three as if it were a single bar. Seems possibly important to keep certain functionality, since the application menu bar is embedded in that very same bar, so local maximize produces the File/Edit/View/etc menus on that window. I could live with that...

But honestly, I would prefer three distinct 1920x1080 monitors, which still afford the ability to drag things around and provide local maximized windows. It might just not be possible though.

And I still have yet to determine if this current method will allow: center-monitor-only 1080p gaming; 5760x1080 gaming; full hardware acceleration using both GPUs in SLI.
Not that I honestly expect to get all that much gaming in on Linux. Even if this does indeed become my "default OS", my Windows7 install will remain for gaming and other Windows-only functionality.