Huge improvements all around, although still far from fglrx.
Phoronix: AMD Catalyst vs. Linux 3.7 + Mesa 9.1-devel Gallium3D Performance
In this article is a large OpenGL performance comparison looking at the frame-rates in different Linux games for different AMD Radeon Linux graphics cards when running the stock Ubuntu 12.10 operating system (Mesa 9.0 + Linux 3.5), the Catalyst Linux driver (fglrx 9.0.2) as found in the Ubuntu Quantal archive, and then when running the very latest Radeon Git code: The Linux 3.7 kernel, Mesa 9.1-devel, and xf86-video-ati 7.0.99 Git.
http://www.phoronix.com/vr.php?view=18184
Huge improvements all around, although still far from fglrx.
Awesome! It's great to see xf86-video-ati make significant improvements in most tests. It's ~half as good as Catalyst in ~half the tests, which is great news indeed. Nice work, AMD devs. I'm eagerly awaiting the day the OSS drivers come within 80-90% performance of Catalyst on most cases and I can switch away from Catalyst 12.6 legacy.
4+ years later, the open source driver still isn't mature.
The worst benchmark results (Reaction Quake and Xonotic) are caused by inefficiency in TTM. 90% of all time is spent in TTM, which moves buffers between VRAM and RAM all the time like crazy, and 10% of time is spent on the rendering. At least we know where the problem is.
Maturity can not be simplified only to performance.
And other features *WOULD* be there if only *legal* department of AMD gave green light. AMD devs had (have?) all necessary patches.
And 4y is too little to get serious performance (on pair with production that was tweaked and developed x0 of years).