Different Unichrome family display drivers
The VIA proprietary drivers
These are considered unstable and unsecure.
The driver that comes with Xorg. Supports VIA CLE266, KM400/KN400, K8M/N800, PM/N800 and CN400 chipsets. Accelerates 2D, 3D, Xvideo and mpeg2 decoding using XvMC. Nowadays the Xorg-driver is mostly unmaintained as the development focus is on OpenChrome-driver.
You can install the Xorg driver with command:
pacman -S xf86-video-via
Another driver with the development focus on stability and clean code. Unichrome driver only supports CLE266, KM400, P4M800 and K8M800 chipsets. Doesn't support accelerated mpeg2-decoding.
You can install the unichrome driver with command:
pacman -S xf86-video-unichrome
The OpenChrome driver
The most advanced and developed driver for Unichromes. Supports CLE266, KM400/KN400/KM400A/P4M800, CN400/PM800/PN800/PM880, K8M800, CN700/VM800/P4M800Pro, CX700, P4M890, K8M890 and P4M900/VN896 chipsets. Accelerates 2D, 3D, Xvideo and mpeg2 decoding using XvMC. This driver is the way to go if you wan't to be on the bleeding edge.
You can install the OpenChrome driver with command:
pacman -S openchrome
Unichrome and OpenGL
OpenGL support for Via's graphic chipsets is seriously outdated. At the moment you will not be able to run more fancy applications, games or compositing desktops like Compiz Fusion that rely on OpenGL as a backend, because the more recent OpenGL extensions are not yet supported in Unichrome 3D driver. You will be able to run simple OpenGL-applications though.
At the time of the writing of this wiki Arch-repo has libgl, unichrome-dri and mesa packages built from the Mesa 7.0.1 -branch.
wiki.openchrome.org states: "The 3D driver that complements the openchrome driver can be obtained from the DRI project. For now you should use the Mesa-6.4 branch; the last version known to work sort of reliably is Mesa-6.4.1."
If you experience X freezes or wierd behaviour when trying to run OpenGL-applications and you absolutelly must have somewhat stable OpenGL-support you should consider rebuilding libgl, unichrome-dri and mesa -packages from the Mesa 6.4.1 -branch.
If you wan't to disable OpenGL alltogether add:
disable "dri" disable "glx"
to the module section of
If you experience problems with DPMS not turning off laptop's backlight, try adding:
Option "VBEModes" "true"
to the device section of