The Linux 3.13 kernel that will be released in the very near future is very worth the upgrade if you are a RadeonSI user -- in particular, the Radeon HD 7000 series GPUs and newer on the Gallium3D Linux graphics driver -- but other open-source graphics driver users as well may also see nice improvements in the new kernel release. Here's some benchmarks showing off the gains found with the Linux 3.13 kernel for Radeon HD and R9 graphics cards.
I'm in the process of publishing a new set of thorough benchmarks comparing the "out of the box" Ubuntu 13.10 performance to using Mesa 10.1-devel (and other new packages via the Oibaf PPA), the Mesa 10.1-devel Git state and then when upgrading to the latest Linux kernel, and lastly comparing these "best possible" open-source driver performance numbers against the closed-source AMD Catalyst driver. This is being done for two articles to look at the Radeon HD 5000/6000 performance with the "R600 Gallium3D" driver and then with the "RadeonSI" Gallium3D driver for the Radeon HD 7000 series graphics cards and newer. Multiple graphics cards are being tested for each of the series. Those results should come out next week.
The Linux 3.13 kernel yields a big difference for RadeonSI users especially so I decided to share some early numbers this weekend due to the imminent release of Linux 3.13. The 3.13 is a big win for newer AMD graphics processors due to enabling DPM by default and other power management improvements. It's been possible on the 3.11/3.12 kernels to manually enable DPM for Radeon GPUs, but with Linux 3.13 most bugs should now be fixed and it's turned on by default. For higher-end GPUs this allows the Radeon DRM driver to dynamically re-clock to its highest power state while down-clocking when idling to save power and reduce heat output: Radeon DPM is fantastic for the open-source driver.
Also responsible for a big boost in the "RadeonSI" GCN era graphics processors with Linux 3.13 is a very important performance fix. Embarrassingly, the open-source AMD Linux driver up to now had a bug where only the render back-ends for the first shader engine were enabled while the rest of the back-ends were accidentally left disabled. This performance fix did land late in the release cycle.
There's also various other open-source Radeon driver improvements found in the Linux 3.13 kernel like HDMI audio support is turned on by default. Plus there's a huge assortment of other Linux 3.13 new features and improvements.
Let's see what it means for the latest Radeon graphics cards when upgrading from Linux 3.12 to 3.13...