xorg.conf and Unity3D multiple monitors

Is it possible to change my xorg.conf so I can use Unity3D?

    Section "ServerLayout"
        Identifier "Layout0"
        Screen 0 "Screen0" 0 0
        Screen 1 "Screen1" RightOf "Screen0"
        Screen 2 "Screen2" RightOf "Screen1"
        Screen 3 "Screen3" RightOf "Screen2"
        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 "Acer AL1916"
        HorizSync 31.0 - 83.0
        VertRefresh 56.0 - 75.0
        Option "DPMS"
    EndSection

    Section "Monitor"
        Identifier "Monitor1"
        VendorName "Unknown"
        ModelName "Acer AL1916"
        HorizSync 31.0 - 83.0
        VertRefresh 56.0 - 75.0
        Option "DPMS"
    EndSection

    Section "Monitor"
        Identifier "Monitor2"
        VendorName "Unknown"
        ModelName "Acer AL1916"
        HorizSync 31.0 - 83.0
        VertRefresh 56.0 - 75.0
        Option "DPMS"
    EndSection

    Section "Monitor"
        Identifier "Monitor3"
        VendorName "Unknown"
        ModelName "Acer AL1916"
        HorizSync 31.0 - 83.0
        VertRefresh 56.0 - 75.0
        Option "DPMS"
    EndSection

    Section "Device"
        Identifier "Device0"
        Driver "nvidia"
        VendorName "NVIDIA Corporation"
        BoardName "GeForce GT 520"
        BusID "PCI:1:0:0"
        Screen 0
    EndSection

    Section "Device"
        Identifier "Device1"
        Driver "nvidia"
        VendorName "NVIDIA Corporation"
        BoardName "GeForce GT 520"
        BusID "PCI:1:0:0"
        Screen 1
    EndSection

    Section "Device"
        Identifier "Device2"
        Driver "nvidia"
        VendorName "NVIDIA Corporation"
        BoardName "GeForce GT 520"
        BusID "PCI:6:0:0"
        Screen 0
    EndSection

    Section "Device"
        Identifier "Device3"
        Driver "nvidia"
        VendorName "NVIDIA Corporation"
        BoardName "GeForce GT 520"
        BusID "PCI:6:0:0"
        Screen 1
    EndSection

    Section "Screen"
        Identifier "Screen0"
        Device "Device0"
        Monitor "Monitor0"
        DefaultDepth 24
        Option "TwinView" "0"
        Option "TwinViewXineramaInfoOrder" "CRT-0"
        Option "metamodes" "CRT-0: 1280x1024_75 +0+0"
        SubSection "Display"
            Depth 24
        EndSubSection
    EndSection

    Section "Screen"
        Identifier "Screen1"
        Device "Device1"
        Monitor "Monitor1"
        DefaultDepth 24
        Option "TwinView" "0"
        Option "metamodes" "CRT-1: 1280x1024_75 +0+0"
        SubSection "Display"
            Depth 24
        EndSubSection
    EndSection

    Section "Screen"
        Identifier "Screen2"
        Device "Device2"
        Monitor "Monitor2"
        DefaultDepth 24
        Option "TwinView" "0"
        Option "metamodes" "CRT-0: 1280x1024_75 +0+0"
        SubSection "Display"
            Depth 24
        EndSubSection
    EndSection

    Section "Screen"
        Identifier "Screen3"
        Device "Device3"
        Monitor "Monitor3"
        DefaultDepth 24
        Option "TwinView" "0"
        Option "metamodes" "CRT-1: 1280x1024_75 +0+0"
        SubSection "Display"
            Depth 24
        EndSubSection
    EndSection

At the moment, if I chose Unity3D, it will just display on 1 screen, if I choose Unity2D it will mirror 1 screen to all screens, so I have to resort to gnome-classic to get all 4 screens to work with the above xorg.conf.