After looking last week at the ATI/AMD Radeon Gallium3D performance under Mesa 8.0 and comparing its performance to Mesa 7.11 and the closed-source AMD Catalyst driver, along with the LLVMpipe driver performance, we're now focusing upon the Nouveau Gallium3D implementation that seeks to provide open-source NVIDIA hardware support. This comparison is pitting Nouveau in Mesa 8.0 against Mesa 7.11 and the official NVIDIA Linux driver.
This updated Nouveau Gallium3D driver testing is being done in an identical manner to last week's Radeon Gallium3D driver testing: on several generations of NVIDIA GeForce graphics cards, the OpenGL performance is being compared against Mesa 7.11, the branched Mesa 8.0-devel Git, and the latest NVIDIA Linux binary driver.
When it comes to Nouveau on Mesa 8.0 the main item to point out is that the "NVC0" / "Fermi" driver for the GeForce 400/500 series does advertise GL Shading Language (GLSL) 1.30 support for OpenGL 3.0.
While other generations of NVIDIA hardware is also capable of the OpenGL 1.30 / GLSL 1.30 support, in Mesa 8.0 the Gallium3D driver for the older hardware is not matching this level -- ideally it will be there for Mesa 8.1. If you missed it, read Eight Reasons You Can Enjoy Mesa 8.0 and Eight Shortcomings Of Mesa 8.0 for additional details about this user-space open-source graphics driver library.
Unfortunately, as you can see from some of the pictures, Nouveau in Mesa 8.0 when paired with the Linux 3.2 kernel is not always ideal. There have been some lock-ups and rendering issues with certain graphics cards at random times. As said before, the best support with Nouveau is generally the GeForce 8/9 series, but depending upon the versions of different components, this reverse-engineered hardware support by the community can be a game of Russian Roulette.