Take 3 NVidia cards GT 640 cards in my case.
Stick them in a PC - No SLI
Add two 23" LCD/LED screens per card for total of 6 screens.
Install Ubuntu (14.04 now, but had same problem with every version after 7.04)
Get the following to work:
Maximize windows per screen (not one big window over all the screens)
Be able to drag a window from one screen to another.
Have hardware acceleration. - have something like 3D Desktop cube or any compiz effects working.
Post detailed instructions how to accomplish said feat.
I double dare anyone to do this.
Pro tip: It can not be done.
My best effort:
6 separate x displays combined into one screen (5760x2160)
No hardware acceleration.
xrandr program version 1.4.1
RandR extension missing
Disabling xinerama - full hardware support, can play games etc. but not move a window from one screen to another.