Radeon Gallium3D R600g Color Tiling Performance
With 2D color tiling enabled by default in the R600 Gallium3D Radeon open-source driver as of this week, here are new benchmarks showing off the OpenGL performance impact of the 1D and 2D tiling methods for this common open-source AMD Linux graphics driver.
Support for 2D color tiling has been a work in progress going back about one year while there was also earlier work in that direction, but not all of the support came together in a sane and stable manner until recently. If using a recent Linux kernel paired with the Mesa 9.0 release or newer, 2D color tiling for the Radeon HD 2000 (R600) through Radeon HD 6000 graphics cards from AMD should be in good shape for handling this performance-optimizing feature. As such, the open-source AMD developers now enabled the feature by default within the xf86-video-ati DDX driver where as up until this week the xorg.conf manually needed the ColorTiling2D option to be enabled.
Back in January I provided some early Radeon Gallium3D 2D color tiling benchmarks and then updated benchmarks in March, but now that everything is deemed stable, this weekend are some new benchmarks using the latest Git this week for Mesa 9.1-devel, the Linux 3.7 kernel, and the xf86-video-ati X.Org driver.
The testing in this article is just from a mid-range Radeon HD 4650 graphics card while a larger open-source comparison plus Catalyst numbers for reference will come in a future article. Holding off on a larger open vs. closed-source driver comparison at the moment is just seeing if anymore performance patches will land in the near future. Until then, there are some recent Ubuntu 12.10 Radeon vs. Catalyst benchmarks on a small selection of modern AMD graphics hardware.
The benchmarking from this Radeon HD 4000 series graphics card on the latest open-source Linux driver was done with no color tiling (the ColorTiling and ColorTiling2D options both disabled from the xorg.conf), only 1D color tiling (the default up until last week; ColorTiling is enabled but ColorTiling2D disabled), and then both 1D/2D color tiling enabled (the new default for R600 through ARUBA graphics cards as of this week's DDX driver Git). The 1D tiling is also known as micro-tiling while 2D is macro-tiling. For those unsure how their Radeon-based Linux system is currently configured, the tiling state is displayed within the /var/log/Xorg.0.log. All benchmarking was handled in a fully automated and reproducible manner using the Phoronix Test Suite benchmarking infrastructure.