xorg-seat0.conf

Section "ServerLayout"
    Identifier      "Seat0"
    Screen      0   "Screen0" 0 0
    Screen      1   "Screen1" LeftOf "Screen0"
    Screen      2   "Screen2" RightOf "Screen0"
EndSection

Section "ServerFlags"
    Option          "Xinerama" "0"
EndSection

#Section "InputClass"
#    Identifier      "ignore other seats"
#    Option          "Ignore" "yes"
#EndSection

#Section "InputClass"
#    Identifier      "Seat0"
#    MatchTag        "Seat0"
#    Option          "Ignore" "no"
#EndSection

Section "Monitor"
    Identifier      "Monitor0"
    Option          "DPMS"
EndSection

Section "Monitor"
    Identifier      "Monitor1"
    Option          "DPMS"
EndSection

Section "Monitor"
    Identifier      "Monitor2"
    Option          "DPMS"
EndSection

Section "Device"
    Identifier      "Device0"
    Driver          "nvidia"
    VendorName      "NVIDIA Corporation"
    BoardName       "GeForce GTX 660"
    BusID           "PCI:1:0:0"
    Screen          0
    Option	        "NoLogo" "True"
    Option 	        "ProbeAllGpus" "false"
EndSection

Section "Device"
    Identifier      "Device1"
    Driver          "nvidia"
    VendorName      "NVIDIA Corporation"
    BoardName       "GeForce GTX 660"
    BusID           "PCI:1:0:0"
    Screen          1
    Option	        "NoLogo" "True"
    Option 	        "ProbeAllGpus" "false"
EndSection

Section "Device"
    Identifier      "Device2"
    Driver          "nvidia"
    VendorName      "NVIDIA Corporation"
    BoardName       "GeForce GTX 660"
    BusID           "PCI:1:0:0"
    Screen          2
    Option	        "NoLogo" "True"
    Option 	        "ProbeAllGpus" "false"
EndSection

Section "Screen"
    Identifier      "Screen0"
    Device          "Device0"
    Monitor         "Monitor0"
    DefaultDepth    24
    Option          "Stereo" "0"
    Option          "metamodes" "DFP-0: nvidia-auto-select +0+0"
    SubSection      "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"
    Identifier      "Screen1"
    Device          "Device1"
    Monitor         "Monitor1"
    DefaultDepth    24
    Option          "Stereo" "0"
    Option          "metamodes" "DFP-1: nvidia-auto-select +0+0"
    SubSection      "Display"
        Depth       24
    EndSubSection
EndSection

Section "Screen"
    Identifier      "Screen2"
    Device          "Device2"
    Monitor         "Monitor2"
    DefaultDepth    24
    Option          "Stereo" "0"
    Option          "metamodes" "DFP-3: nvidia-auto-select +0+0"
    SubSection      "Display"
        Depth       24
    EndSubSection
EndSection