Dual Screen

For an update see Hardware Configuration, Audio/Video#Multiple Monitors.

Nvidia Dual Screen

If you want a simple way to get two equal sized screens working in dual screen mode then install nvidia-xconfig and type the following:

# nvidia-xconfig --twinview

If you have different sized screens it becomes tricky. I still used the above command but had to edit the X config file which is either: /etc/X11/xorg.config (Most current FreeBSD versions) /etc/X11/XF86Config (Old FreeBSD versions and PCBSD)

Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0"
    Screen      1  "Screen0 (2nd)" RightOf "Screen0"
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
EndSection

Section "ServerFlags"
    Option         "Xinerama" "1"
EndSection

Section "Monitor"
    Identifier     "Monitor0"
    HorizSync       31.5 - 48.5
    VertRefresh     50.0 - 90.0
    Option         "DPMS"
EndSection

Section "Device"
    Identifier     "Card0"
    Driver         "nvidia"
    BoardName      "GeForce FX 5200"
    BusID          "PCI:1:0:0"
    Screen          0
EndSection

Section "Device"
    Identifier     "Card0 (2nd)"
    Driver         "nvidia"
    BoardName      "GeForce FX 5200"
    BusID          "PCI:1:0:0"
    Screen          1
EndSection

Section "Screen"
    Identifier     "Screen0"
    Device         "Card0"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "UseEdidFreqs" "True"
    Option         "MetaModes" "1024x768, 1024x768"
    SubSection     "Display"
        Depth       24
        Modes      "1600x1200" "1280x1024" "1024x768" "800x600" "640x480"
    EndSubSection
EndSection

Section "Screen"
    Identifier     "Screen0 (2nd)"
    Device         "Card0 (2nd)"
    Monitor        "Monitor0"
    DefaultDepth    24
    Option         "UseEdidFreqs" "True"
    Option         "MetaModes" "1280x1024, 1280x1024"
    SubSection     "Display"
        Depth       24
        Modes      "1600x1200" "1280x1024" "1024x768" "800x600" "640x480"
    EndSubSection
EndSection

If you want to quickly try out new configurations then you can hit: Ctrl-Alt-Backspace to restart X, this is very useful if you boot directly into a GUI because this saves you rebooting.