Abstracts from the homepage
http://www.probo.com/timr/savage40.html
"VIA/S3 has release an updated version of THEIR Savage driver. It forked off of my source base about 3 years ago, so there are significant differences, but it looks like they have addressed a number of issues. This includes motion compensation support for MPEG playback (XvMC), and the long-awaited DRI driver for 3D OpenGL code. The DRI driver is only for the ProSavage and Twister chips, so it won't help Savage/IX or SuperSavage users. If you want to download the source and build it, try
http://www.linux.org.uk/~alan/S3.zip. It was built for XFree86 4.2.0; the DRI code, in particular, will need a lot of work for XFree86 4.3.0. However, this driver has been submitted to XFree86, so with any luck it will be a standard part of XFree86 4.4. "
But hang on....
At the end of the page (Known Issues) it says:
"DRI/OpenGL/Mesa support.
There is currently no DRI driver for the Savages for XFree86 4.x, which means that OpenGL applications are entirely simulated in software. There was work going on at one time to add this support, by the same fellow who did the UtahGLX driver for XFree86 3.3.6, but his e-mail address no longer responds."
So what do make of this. I think it not supported, but it works in Windows, at least I can choose Hardware acceleration there, but if it really works or not must be unspoken of.