Earlier this month I shared some basic OpenGL benchmarks between AMD's Kaveri APU on the Catalyst driver and the open-source RadeonSI Gallium3D driver. Now that more time has passed I'm back with another round of Linux graphics driver testing on the AMD A10-7850K, this time looking at the impact when forcing Dynamic Power Management and toggling color tiling for maximum performance.
The testing earlier this month between the open-source RadeonSI Gallium3D driver and the AMD Catalyst driver was done with stock settings, which turned out to deliver crippling numbers to the new APU. With today's tests the A10-7850K performance is focused on:
- Ubuntu 14.04 LTS in its current development form when using Mesa 10.1-devel from the xorg-edgers PPA and using its stock Linux 3.13 kernel.
- The same configuration as above but manually forcing Radeon DPM (Dynamic Power Management) via the radeon.dpm=1 kernel module parameter. For the Linux 3.13 kernel it didn't end up enabling Kaveri APU for dynamic re-clocking but should for Linux 3.14. It ended up being a difference of 200MHz vs. 720MHz for the Radeon R7 graphics core on the A10-7850K.
- The same configuration as above with Radeon DPM and then also setting the ColorTiling and ColorTiling2D options in the xorg.conf for the xf86-video-ati DDX. Color tiling is a performance-boosting feature but not enabled by default for Kaveri within the Radeon X.Org driver. This third configuration represents the best possible open-source AMD Kaveri APU performance at the moment.
The Catalyst driver wasn't tested for this run due to the lack of a patched Catalyst driver that supports both AMD's Kaveri APUs and the Linux 3.13 kernel. New open vs. closed-source driver testing will come in the weeks ahead, especially with RadeonSI Gallium3D soon supporting OpenGL 3.3. I'm also hopeful of Catalyst correcting some of its performance issues in the coming releases.
The Ubuntu 14.04 open-source Kaveri APU driver testing happened with the A10-7850K paired with DDR3-2133MHz memory on a Gigabyte F2A88XM-D3H -- this is our second AMD Kaveri Linux system running at Phoronix that will be running in the automated benchmarking test farm. All benchmarking was handled, as always, via the Phoronix Test Suite with results hosted on OpenBenchmarking.org for cross-comparisons and collaborative opportunities.