Device Section; Twinview - Silicon Graphics Virtu VN200 Hardware User's Manual

System Procedures

Device Section

TwinView

54
The device section defines the configuration parameters for a specific graphics card.
There is typically one "Device" section for each graphics card in the system. The device
section can make one graphics card with two channels act like two graphics cards using
Screen option. A large number of options are available for the setting the device. It is best
refer to the NVIDIA README file for specific information about the graphics card
configuration parameters. Some examples are given below:
Section "Device"
Identifier "Device[0]"
BoardName "Quadro FX 5600"
BusID "1:0:0" # should match up with output of lspci (in decimal)
Driver "nvidia" # use "nvidia" (proprietary driver), not "nv" (OSS)!!!
VendorName "NVidia"
Option "TwinView" "true" # turn on dual channel mode
Option "MetaModes" "nvidia-auto-select,nvidia-auto-select"
Option "TwinViewOrientation" "LeftOf"
EndSection
TwinView is an NVIDIA extension with supports multiple displays from a single GPU.
It turns on the dual channel mode of the GPU allowing for the a single X server to be
configured across the two channels. This has an advantage over other techniques such as
Xinerama in that:
• A single X screen is used. The NVIDIA driver conceals all information about
multiple display devices from the X server; as far as X is concerned, there is only
one screen.
• Both display devices share one frame buffer. Thus, all the functionality present on a
single display (e.g. accelerated OpenGL) is available with TwinView.
• No additional overhead is needed to emulate having a single desktop
To enable TwinView, you must specify the following options in the Device section of your
xorg.conf file:
Option "TwinView"
Option "MetaModes" "<list of metamodes>"
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