I'm copy-pasting below what I've entered into Linux Incompatibility list (http://leenooks.com/233)

Reason: No specs from manufacturer. There's a unichrome.sourceforge.net project for an OSS driver "via", which is included in xorg 6.7.x and up (don't know XFree situation), which in turn is included in many newer distros. The problem is that it's not 64-bit clean yet, so currently no "via" driver exist for amd-64 flavors. At least it's so with Ubuntu/Kubuntu.

Functionality (from 0 to 100% of full functionality): It works with generic "vesa" driver, at standard VESA resolutions at 60Hz. (Unaccelerated)

URL for more information: https://bugzilla.ubuntu.com/show_bug.cgi?id=8208

Contact: aramazan ÄT myrealbox D0T cöm

Notes:
* The driver works on i386 flavor of Linux installed on a K8M800 (amd64) mainboard (amd64 running in i386 mode)
* Should check unichrome.sf.net (or the Ubuntu bugzilla entry above) occasionally for amd64 compatibility.

Recommended alternatives:
Use primarily nVidia (or as a fall back) ATI on amd64 machines. They also don't provide specs for OSS driver developers, but at least nVidia's closed source drivers work well on wide range of Linux flavors.