Comment 0 for bug 367941

Older Sony Vaios have 2 graphics adapters, usually one from Intel and one from nVidia (e.g. on the Vaio SZ650N, there is an Intel GM965 and an nVidia GeForce 8400M GS), which you can select with a hardware switch when the notebook is off.

Ubuntu supports acceleration of both chips with open source (Intel) and proprietary (nvidia) drivers, but installing both means that the 3D setup gets clobbered. The current workaround is to have two xorg.conf files, one for each adapter, a couple of backed-up 3D libraries and a script that selects the right combination. The script in its current state is specific to particular nvidia driver versions (even a minor version change would break it), so is limited, but does work.

see http://doube.org/hardy-vaio.html#video and http://doube.org/jaunty-vaio.html#video for details.