Catalyst 14.4 Has Advantages Over Linux 3.15 + Mesa 10.3 Git
After earlier this week doing an Intel vs. Radeon vs. Nouveau comparison using the very latest open-source Linux graphics driver code in the form of Mesa 10.3-devel and the Linux 3.15 kernel, here's benchmark results comparing the updated open-source AMD Radeon performance on Ubuntu 14.04 LTS against the Catalyst 14.4 Linux graphics driver.
Due to the Radeon DRM regressions noted in the earlier article around the GCN era hardware (Radeon HD 7000 series and newer), this comparison was limited to the few graphics processors we could run on the Linux 3.15 kernel earlier in the week. We're still waiting for the mainline fixes to address the Radeon fallout on Linux 3.15, which still should land in plenty of time for the kernel's official release in the weeks ahead. Thus the graphics cards up for comparison today are the Radeon HD 5770, HD 5830, HD 6870, and HD 6950. With our upcoming Ubuntu 14.04 LTS vs. Windows 8.1 performance comparison, at least there we're able to use the newer HD 7000 and Rx 200 series GPUs due to using just the Catalyst drivers and not the currently problematic open-source Git code.
The open-source driver tests were using the Linux 3.15 Git kernel from the Ubuntu Mainline Kernel PPA while the Oibaf PPA was also loaded for the Mesa 10.3-devel Git master snapshot and xf86-video-ati 7.3.99 Git. With the Catalyst testing we were using the 14.4 driver release (fglrx 14.10.2 / OpenGL 4.3.12874). For kernel compatibility with the binary blob, we also backed down from Linux 3.15 Git to Linux 3.13 stable as shipped by Ubuntu 14.04 LTS. The same Intel Core i7 4770K system was used throughout all testing and no changes were made during the testing process aside from the software driver and graphics card swapping as noted.
The updated open-source driver stack should represent what most AMD open-source Linux desktop users will experience either now -- if they're habitual Git users or soon with rolling-release distributions -- and in the weeks/months ahead. There's also the ability to squeeze a few more frames out of the system by setting some special environment variables and such on the open-source driver, but as usual, we're focusing as close to out-of-the-box as possible given that's what most desktop Linux users will encounter when running the drivers themselves.
All of our AMD Linux benchmarking for this article was done by the Phoronix Test Suite.