Mesa Version?

If you are asking about 3d the support is zero. AMD only releases a hollow shell. There is a non-free component and the shell doesn't work with out it. Thus no 3d on Trisquel. I believe there may be some 2d support though.

I'm aware of the lack of 3d support, but the 2d support that I've tried isn't all that great. I was wondering if the version of Mesa was older to see if compiling a newer version would help. I'd really rather not use anything non-free.

I don't think that Mesa has to do with 2D at all. Perhaps try a newer kernel instead, probably won't help either.

As a user of an AMD card I've pretty much gotten used to slow, jittery scrolling and graphical artifacts...

I believe from glxinfo command (from the mesa-utils package) that the Mesa version is 7.11 FWIW.

Here you can find new Linux-libre versions http://www.fsfla.org/svnwiki/selibre/linux-libre/

A search with the Synaptic package manager or with apt-cache (or this site) gives you the answer.

Thanks. I actually did both things and installed the linux-libre 3.5.2 kernel and upgraded Mesa to 8.04 from the Debian Sid repository. It more than doubled the framerate in glxgears, but there's still an issue of tearing during video playback.

Is this a desktop system? Even though I'm not a big fan of nVidia there is the nouveau driver. It's reverse engineered and works good enough on older nVidia chipsets. The current recommendation overall from the experts is to go with the 9500GT. A number of people here have bought one.

You can find a 9500GT card under Accessories & Other Products:

http://libre.thinkpenguin.com/

Personally I'd recommend upgrading the motherboard or just replacing the system and getting Intel graphics. They are pretty good now (comparable to low end nVidia) and certain features are better supported (video acceleration). Comparatively the 9500GT is about on par with the latest Intel graphics chipsets.

Obviously the 9500GT is the cheaper option for an older system.

I would, do all of that, but I'm just not willing to part with my system. The GPU is a Radeon HD 7970. The CPU and motherboard are a Xeon e3-1240 v2 and an Asus P8BWS. It's my primary machine. I do also have an HP netbook that I'm working on removing the BIOS whitelist on so I can swap Ubuntu for Trisquel, but that's not much of an issue. I would just like to drop the proprietary drivers because they're the only thing holding me back. I bought the card before I realized that the were fully free distros out there, and seeing as it is so high end, I don't want to "trade down."