> The sad fact is that the open-source drivers are shit for anything more
> that a 15 years old modded Quake 3 engine ( like those phoronix 3D tests
> ) and the only blobs that work out of the box and can match the Windows
> drivers in performance and features are Nvidia's ...
When I bought a new GPU last year I opted for the Radeon HD6950 over the new 7850, given that they have roughly the same performance and I figured that the older series would have better support in the open source drivers.
Performance in TF2 was horrible (unplayable) when the Steam beta came out and I had to compile mesa 9 myself for the required features because it wasn't in Debian yet. Then, sometime early this year, something clicked and performance just went through the roof. I don't know whether it was mesa 9.1, or it now being in Debian and properly integrated with the X stuff, or improvements on the kernel side.
In any case, since then I was running Team Fortress 2 and Left 4 Dead 2 at native resolution (2560x1440) with settings above those recommended by the games and everything runs smoothly (in the 25 to 60 fps range according to the games themselves). I haven't compared the raw numbers to Windows, but since it's smooth I don't care.
I'd rather boot into Windows than install fglrx again, so this suits me rather well. For comparison, Serious Sam 3: BFE, a game with a more demanding graphics engine, is quite smooth in most places but has places where the fps drop below 20.