I would like to launch my game only in the external monitor which I have attached to my laptop with hdmi cable. This is my current xorg.conf

# nvidia-xconfig: X configuration file generated by nvidia-xconfig
# nvidia-xconfig:  version 319.60  (buildmeister@swio-display-x64-rhel04-15)  Wed Sep 25 15:17:31 PDT 2013

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
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"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       28.0 - 33.0
    VertRefresh     43.0 - 72.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "metamodes" "1024x786,NULL;1280x720,NULL;NULL,1680x1050;NULL,1920x1080"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection

Although with this config nothing changes (I have my game displayed in the laptop screen and exceeding a little bit onto the external monitor since I set it to be in 1920x1080)

I have read this https://help.ubuntu.com/community/XineramaHowTo but with no luck of solving this issue.

The only temporary solution for this problem now is to manually switch of the laptop display and then launch the game.