$ cat /etc/X11/xorg.conf
Section "ServerLayout"
        Identifier     "X.org Configured"
        Screen      0  "Screen0" 0 0
        Screen      1  "Screen1" RightOf "Screen0"
        InputDevice    "Mouse0" "CorePointer"
        InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "InputDevice"
        Identifier  "Keyboard0"
        Driver      "kbd"
EndSection

Section "InputDevice"
        Identifier  "Mouse0"
        Driver      "mouse"
        Option      "Protocol" "auto"
        Option      "Device" "/dev/input/mice"
        Option      "ZAxisMapping" "4 5 6 7"
EndSection

Section "Monitor"
        Identifier   "Monitor0"
        VendorName   "Monitor Vendor"
        ModelName    "Monitor Model"
EndSection

Section "Monitor"
        Identifier   "Monitor1"
        VendorName   "Monitor Vendor"
        ModelName    "Monitor Model"
EndSection

Section "Monitor"
        Identifier   "Monitor2"
        VendorName   "Monitor Vendor"
        ModelName    "Monitor Model"
EndSection

Section "Monitor"
        Identifier   "Monitor3"
        VendorName   "Monitor Vendor"
        ModelName    "Monitor Model"
EndSection

Section "Device"
        ### Available Driver options are:-
        ### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
        ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",
        ### <percent>: "<f>%"
        ### [arg]: arg optional
        #Option     "SWcursor"                  # [<bool>]
        #Option     "kmsdev"                    # <str>
        #Option     "ShadowFB"                  # [<bool>]
        #Option     "AccelMethod"               # <str>
        #Option     "PageFlip"                  # [<bool>]
        #Option     "ZaphodHeads"               # <str>
        #Option     "DoubleShadow"              # [<bool>]
        Identifier  "Card0"
        Driver      "modesetting"
        BusID       "PCI:0:2:0"
EndSection

Section "Device"
        Identifier  "Card1"
        Driver      "nvidia"
        BusID       "PCI:1:0:0"
        Option      "Coolbits" "31"
EndSection

Section "Screen"
        Identifier "Screen0"
        Device     "Card0"
        Monitor    "Monitor0"
        Option         "AllowEmptyInitialConfiguration" "True"
        SubSection "Display"
                Viewport   0 0
                Depth     1
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     4
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     8
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     15
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     16
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     24
        EndSubSection
EndSection

Section "Screen"
        Identifier "Screen1"
        Device     "Card1"
        Monitor    "Monitor1"
        Option "AllowEmptyInitialConfiguration" "True"
        SubSection "Display"
                Viewport   0 0
                Depth     1
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     4
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     8
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     15
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     16
        EndSubSection
        SubSection "Display"
                Viewport   0 0
                Depth     24
        EndSubSection
EndSection