FeatureDisplaySwitching
From cchtml.com
The Proprietary Driver supports runtime display switching.
To list displays that are connected
$ aticonfig --query-monitor Connected monitors: lvds, tmds1 Enabled monitors: lvds
To switch between different display outputs (to enable the Laptop LCD and DVI LCD as above).
$ aticonfig --enable-monitor=lvds,tmds1 Using /etc/X11/xorg.conf
To allow the driver to find an enable displays automatically.
$ aticonfig --enable-monitor=auto Using /etc/X11/xorg.conf