ATI Graphics Cards

First of all, please call the operating system GNU/Linux: http://www.gnu.org/gnu/why-gnu-linux.html

Then, I feel sorry for you but I do not believe there exists any trick to have a better experience with the radeon and, to the best of my knowledge, it is now the only Free driver working with recent cards. Notice by the way that the real problem is not the GPL driver but the proprietary firmware that is required for many of its features.

I used to have an ATI Radeon X850XT. What tricks I found for better 3D support? Easy. I bought a new motherboard with an integrated Intel X4500. I know, it sucks. Both the fact that this is the only way for reliable, non reverse engineered 3D support and the performance of the card. Some older games run with wine, unfortunately not even all games that are supposed to run well in wine run! Serious Sam 2 for example has huge graphical errors that make it unplayable (some parts of models don't get displayed and you get weird polygons floating around instead).

For gaming I emulate old-school 16-bit consoles (not out of desperation mind you, I'm a huge fan of the Mega Drive and the SNES also has it's golden titles). I also own a real Mega Drive. The best way for gaming is to buy a console and leave the PC for emulation of old 2D games. DOSBox works very well.

I know the situation sucks, I'm not trying to hide the fact that you will have to do without many modern games. Crossfire TO is supposed to run natively, as an add-on for UT 2004, but it is so goddamn hard to install it all properly (install UT, install the correct patch, install Crossfire TO, patch that too) that I never managed to do it. Half-Life 1 and Counter-Strike are supposed to work with wine (but I never got it that way). Half-Life 2 is obviously out of question with the X4500, it says it's Direct X10 compatible, but it has barely enough performance to run Direct X8 titles (just my personal feeling about it, no measurements made or something).

The good side: there are free software games like Nexuiz (a very good UT look-a-like) and OpenArena (Quake3 engine, Quake3 feel). Many free software mini-games that are quite fun if you don't expect them to be of the quality of full-price titles and like that sort of gaming. Baldurs Gate 1 and 2 work flawlessly! Infinity Engine games from Bioware probably all work flawlessly, Icewind Dale 1 and 2 sure do! Also the DOSBox emulated any DOS title I threw at it without any kinds of errors. If you like old Lucas Arts adventures, there is ScummVM (which is in the repository of Trisquel, yeah!) which allows you to play all of them perfectly.

Good luck.

Hi!

I also use Trisquel with an AMD/ATI GPU. I don't know any exciting
tricks concerning that. It doesn't seem like AMD GPUs will run in full
capacity in a completely free system any time soon. AMD doesn't allow
it. See:
https://trisquel.info/en/forum/3d-and-free-software-trisquel#comment-4170

I heard that almost all Intel GPUs are fully capable in a free
systems such as Trisquel.

I haven't played many computer games since I started using only free
software, but one game I've played and really liked is 2D strategy
called “The Battle for Wesnoth”. You can find it in the repository.

I also found out that you can do 3D modelling with Blender without
hardware 3D acceleration, bearing only little inconveniences.

It should be added, that the drivers for 3D support are there, they just require the binary firmware to be loaded at runtime to execute some functions (like 3D rendering). AMD does not want to make that firmware open source. An AMD/ATI official stated in a forum that this is due to their DRM. It is inside the firmware and making it open source will defeat the purpose of the DRM, because it will be quite easy to just work around it. So the official version is not that they are afraid of someone else stealing some important information from the firmware or something like that. Just the DRM.