I just performed a fresh install of Ubuntu 14.04. I have 3 Nvidia Quadro Cards powering three monitors. I used nvidia-settings to enable the three monitors:
*NOTE: The forum will not let me post the image until I have at least "10 reputation". I don't think the image is necessary for understanding, it just shows that all three monitors are enabled in the Nvidia Settings Window. If you need it, I can PM it to you.
After rebooting all three monitors are being used, but only the primary monitor has a desktop. I can move the mouse to the other two monitors just fine, but the mouse pointer turns into an 'X', and I am unable to drag windows to them. When I try to drag a window onto the other monitor, the desktop acts as if they are not there and tries to dock the window on that side of my primary monitor (desktop). The monitors are black and display no unity launcher or anything. Here is my xorg.conf file:
# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig: version 304.117 (buildmeister@swio-display-x86-rhel47-01) Tue Nov 26 22:29:40 PST 2013
# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 331.20 (buildd@roseapple) Mon Feb 3 15:07:22 UTC 2014
Section "ServerLayout"
Identifier "Layout0"
Screen 0 "Screen0" 0 0
Screen 1 "Screen1" RightOf "Screen0"
Screen 2 "Screen2" RightOf "Screen1"
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
Option "Xinerama" "0"
EndSection
Section "Files"
EndSection
Section "InputDevice"
# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection
Section "InputDevice"
# generated from default
Identifier "Keyboard0"
Driver "kbd"
EndSection
Section "Monitor"
# HorizSync source: edid, VertRefresh source: edid
Identifier "Monitor0"
VendorName "Acer"
ModelName "Acer X223W"
HorizSync 31.0 - 83.0
VertRefresh 56.0 - 75.0
Option "DPMS"
EndSection
Section "Monitor"
# HorizSync source: unknown, VertRefresh source: unknown
Identifier "Monitor1"
VendorName "Acer"
ModelName "Acer X223W"
HorizSync 0.0 - 0.0
VertRefresh 0.0
Option "DPMS"
EndSection
Section "Monitor"
# HorizSync source: unknown, VertRefresh source: unknown
Identifier "Monitor2"
VendorName "Acer"
ModelName "Acer X223W"
HorizSync 0.0 - 0.0
VertRefresh 0.0
Option "DPMS"
EndSection
Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "Quadro 600"
BusID "PCI:4:0:0"
EndSection
Section "Device"
Identifier "Device1"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "Quadro FX 580"
BusID "PCI:5:0:0"
EndSection
Section "Device"
Identifier "Device2"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "Quadro FX 580"
BusID "PCI:9:0:0"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "Stereo" "0"
Option "nvidiaXineramaInfoOrder" "DFP-0"
Option "metamodes" "nvidia-auto-select +0+0"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSection
Section "Screen"
Identifier "Screen1"
Device "Device1"
Monitor "Monitor1"
DefaultDepth 24
Option "Stereo" "0"
Option "metamodes" "nvidia-auto-select +0+0"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSection
Section "Screen"
Identifier "Screen2"
Device "Device2"
Monitor "Monitor2"
DefaultDepth 24
Option "Stereo" "0"
Option "metamodes" "nvidia-auto-select +0+0"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSection
If I look at System Settings->Displays, only the primary monitor will show up, it will not detect the other displays.
Here is the output of: /usr/lib/nux/unity_support_test --print
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: Quadro 600/PCIe/SSE2
OpenGL version string: 4.2.0 NVIDIA 304.117
Not software rendered: yes
Not blacklisted: yes
GLX fbconfig: yes
GLX texture from pixmap: yes
GL npot or rect textures: yes
GL vertex program: yes
GL fragment program: yes
GL vertex buffer object: yes
GL framebuffer object: yes
GL version is 1.4+: yes
Unity 3D supported: yes
Edit 05/06/2014:
After fighting with and learning about how X11 works over the last few days, I think I need to restate the question I have. I think Xinerama is what I need to use, with this computer, I had it configured correctly on Ubuntu 12.04 without any issues, but an update to unity broke everything; so I upgraded to 14.04. Until I can replace X11 with MIR or Wayland, I would like to get Xinerama to work with my current version of Unity, which is 7.2.0.
When I enable Xinerama in my xorg.conf, I am able to log in and can see the background on all three screens, but unity fails to load; something fails with compiz. If I reboot unity, I am able to get the desktop to load and open GUI applications, but I cannot drag them to other monitors. If I try, they are not rendered on the other screens, although I am still able to interact with them and drag them back (only by remembering where the mouse was when I drag released them).
Has anyone successfully gotten Xinerama to work with multiple monitors and GPUs with 3D acceleration and X11 support?
Does anyone know of a workaround such as mosaic mode with an add-ons?
Is there a good alternative to Unity/X11 that is stable and supports multimonitor desktops?
Does the nouveau driver support multi monitor better than the NVidia driver?
Would upgrading to the newer Nvidia Drivers (I have nvidia-current: 304.117) resolve these issues?