I've installed Ubuntu 12.04 this weekend and have had problems getting Unity3d to work with my triple monitor set-up. I've installed the latest nVidia drivers for my 2 nVidia video cards and have used NVIDIA X Server Settings to configure everything. If I stick each monitor on a separate X screen, all but the primary X screen will appear white and the cursor will be a black X. I can start a terminal on this screen but cannot drag other windows to it. If I kill the "Nautilus" process, the white background disappears and I see my desktop background, but my cursor is still an X and I still cannot drag windows to it. If I enable TwinView, I can get one screen on two monitors to work properly, but the white screen remains on my third monitor. In addition, I don't like using TwinView because my full-screen applications get stretched. My current solution is to "Enable Xinerama", use all separate X screens and revert to Unity2d. I'd love a solution to this as Ubuntu 12.10 is not planned to support Unity-2d and prefer the aesthetics of 3d anyways. I can provide Xorg.conf for all configurations and any other suggested diagnostic information. Below is my closest-to-working xorg.conf: # nvidia-settings: X configuration file generated by nvidia-settings # nvidia-settings: version 295.33 (buildd@zirconium) Fri Mar 30 13:38:49 UTC 2012 Section "ServerLayout" Identifier "Layout0" Screen 0 "Screen0" RightOf "Screen2" Screen 1 "Screen1" RightOf "Screen0" Screen 2 "Screen2" 0 0 InputDevice "Keyboard0" "CoreKeyboard" InputDevice "Mouse0" "CorePointer" Option "Xinerama" "1" EndSection Section "Files" EndSection Section "InputDevice" Identifier "Mouse0" Driver "mouse" Option "Protocol" "auto" Option "Device" "/dev/psaux" Option "Emulate3Buttons" "no" Option "ZAxisMapping" "4 5" EndSection Section "InputDevice" Identifier "Keyboard0" Driver "kbd" EndSection Section "Monitor" Identifier "Monitor0" VendorName "Unknown" ModelName "Microvitec PLC MV191" HorizSync 30.0 - 81.0 VertRefresh 56.0 - 75.0 Option "DPMS" EndSection Section "Monitor" Identifier "Monitor1" VendorName "Unknown" ModelName "CRT-1" HorizSync 28.0 - 55.0 VertRefresh 43.0 - 72.0 Option "DPMS" EndSection Section "Monitor" Identifier "Monitor2" VendorName "Unknown" ModelName "Microvitec PLC MV191" HorizSync 30.0 - 81.0 VertRefresh 56.0 - 75.0 Option "DPMS" EndSection Section "Monitor" Identifier "Monitor3" VendorName "Unknown" ModelName "Microvitec PLC MV191" HorizSync 30.0 - 81.0 VertRefresh 56.0 - 75.0 EndSection Section "Device" Identifier "Device0" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "GeForce GTS 450" BusID "PCI:1:0:0" Screen 0 EndSection Section "Device" Identifier "Device1" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "GeForce 9500 GT" BusID "PCI:2:0:0" EndSection Section "Device" Identifier "Device2" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "GeForce GTS 450" BusID "PCI:1:0:0" Screen 1 EndSection Section "Device" Identifier "Device3" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "GeForce GTS 450" BusID "PCI:1:0:0" Screen 2 EndSection Section "Screen" Identifier "Screen0" Device "Device0" Monitor "Monitor0" DefaultDepth 24 Option "TwinView" "0" Option "metamodes" "DFP-0: 1280x1024_75 +0+0; DFP-0: 1280x1024 +0+0" SubSection "Display" Depth 24 EndSubSection EndSection Section "Screen" Identifier "Screen1" Device "Device1" Monitor "Monitor1" DefaultDepth 24 Option "TwinView" "0" Option "metamodes" "nvidia-auto-select +0+0" SubSection "Display" Depth 24 EndSubSection EndSection Section "Screen" Identifier "Screen2" Device "Device2" Monitor "Monitor2" DefaultDepth 24 Option "TwinView" "0" Option "metamodes" "DFP-2: 1280x1024_75 +0+0; DFP-2: nvidia-auto-select +0+0" SubSection "Display" Depth 24 EndSubSection EndSection Section "Screen" Identifier "Screen3" Device "Device3" Monitor "Monitor3" DefaultDepth 24 Option "TwinView" "0" Option "metamodes" "DFP-2: nvidia-auto-select +0+0" SubSection "Display" Depth 24 EndSubSection EndSection Section "Extensions" Option "Composite" "Disable" EndSection Other people have had similar issues. I haven't been successful at any of the few suggestions submitted. Can not get Dual Monitors to work on Different GPUs http://askubuntu.com/questions/30412/3-monitors-with-2-video-cards-not-working?rq=1 How to get second display to work alongside primary display? http://askubuntu.com/questions/148007/multiple-monitors-only-work-with-unity-2d/201086#201086 xorg.conf and Unity3D?