/etc/bumblebee/xorg.conf.nvidia

Section "ServerLayout"
    Identifier  "Layout0"
    Option      "AutoAddDevices" "false"
    Option      "AutoAddGPU" "false"
EndSection

Section "Device"
    Identifier  "DiscreteNvidia"
    Driver      "nvidia"
    VendorName  "NVIDIA Corporation"

#   If the X server does not automatically detect your VGA device,
#   you can manually set it here.
#   To get the BusID prop, run `lspci | egrep 'VGA|3D'` and input the data
#   as you see in the commented example.
#   This Setting may be needed in some platforms with more than one
#   nvidia card, which may confuse the proprietary driver (e.g.,
#   trying to take ownership of the wrong device). Also needed on Ubuntu 13.04.
    BusID "PCI:1:0:0"

#   Setting ProbeAllGpus to false prevents the new proprietary driver
#   instance spawned to try to control the integrated graphics card,
#   which is already being managed outside bumblebee.
#   This option doesn't hurt and it is required on platforms running
#   more than one nvidia graphics card with the proprietary driver.
#   (E.g. Macbook Pro pre-2010 with nVidia 9400M + 9600M GT).
#   If this option is not set, the new Xorg may blacken the screen and
#   render it unusable (unless you have some way to run killall Xorg).
    Option "ProbeAllGpus" "false"

    Option "NoLogo" "true"
    Option "UseEDID" "false"
    Option "UseDisplayDevice" "none"
EndSection

Section "Monitor"
    Identifier   "VGA1"
        Modeline "1440x900_60.00"  106.50  1440 1528 1672 1904  900 903 909 934 -hsync +vsync
        Option  "PreferredMode"  "1440x900_60.00"
        Option  "Primary" "true"
        Option  "LeftOf" "LVDS1"
EndSection