Excuse me first for my broken English I have 3 monitors on two Nvidia GT220. Unity 2D works fine after using the proprietary drivers. But no way to use compiz effects. I'm on Ubuntu 11.10 (I also tested for curiosity 12.04 for the same result) I noticed in the "System Settings" / "details" that my graphics card is not recognized (graphics card "unknown") and "View" only returns me my first screen (with the correct resolution) also in unknown. $ lspci | grep VGA 01:00.0 VGA compatible controller: NVIDIA Corporation GT216 [GeForce GT 220] (rev a2) 05:00.0 VGA compatible controller: NVIDIA Corporation GT216 [GeForce GT 220] (rev a2) xorg.conf : Section "ServerLayout" Identifier "Layout0" Screen 0 "Screen0" 0 0 Screen 1 "Screen1" Below "Screen0" Screen 2 "Screen2" RightOf "Screen0" InputDevice "Keyboard0" "CoreKeyboard" InputDevice "Mouse0" "CorePointer" Option "Xinerama" "1" 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 "Unknown" ModelName "Acer V243HL" HorizSync 30.0 - 80.0 VertRefresh 55.0 - 75.0 Option "DPMS" EndSection Section "Monitor" # HorizSync source: edid, VertRefresh source: edid Identifier "Monitor1" VendorName "Unknown" ModelName "LG Electronics L1920P" HorizSync 30.0 - 83.0 VertRefresh 56.0 - 75.0 Option "DPMS" EndSection Section "Monitor" # HorizSync source: edid, VertRefresh source: edid Identifier "Monitor2" VendorName "Unknown" ModelName "Acer V243HL" HorizSync 30.0 - 80.0 VertRefresh 55.0 - 75.0 Option "DPMS" EndSection Section "Device" Identifier "Device0" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "GeForce GT 220" BusID "PCI:1:0:0" EndSection Section "Device" Identifier "Device1" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "GeForce GT 220" BusID "PCI:5:0:0" Screen 0 EndSection Section "Device" Identifier "Device2" Driver "nvidia" VendorName "NVIDIA Corporation" BoardName "GeForce GT 220" BusID "PCI:5:0:0" Screen 1 EndSection Section "Screen" Identifier "Screen0" Device "Device0" Monitor "Monitor0" DefaultDepth 24 Option "TwinView" "0" Option "TwinViewXineramaInfoOrder" "DFP-0" Option "metamodes" "1920x1080_60_0 +0+0; nvidia-auto-select +0+0" SubSection "Display" Depth 24 EndSubSection EndSection Section "Screen" Identifier "Screen1" Device "Device1" Monitor "Monitor1" DefaultDepth 24 Option "TwinView" "0" Option "metamodes" "CRT: 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: nvidia-auto-select +0+0" SubSection "Display" Depth 24 EndSubSection EndSection Section "Extensions" Option "Composite" "Disable" EndSection Have you any idea? thanks