On Monday AMD made publicly available the release candidate to the Catalyst 14.4 Linux driver that brings full OpenGL 4.4 support. Some Phoronix readers have reported performance changes with this new driver update, so I have done some comparison tests on several AMD Radeon graphics drivers to see how the performance compares with Catalyst 14.4 on Ubuntu Linux.
For this testing I tested the Catalyst 14.4 RC from Monday (fglrx 14.10.2 / OpenGL 4.3.12874) and compared it to the Catalyst driver packaged within the Ubuntu 14.04 "Trusty Tahr" archive, given that most Ubuntu Linux AMD customers will likely be using that Ubuntu-packaged driver. The packaged driver in Ubuntu 14.04 was fglrx 13.35.5 / OpenGL 4.3.12798 (Catalyst 14.3).
I used four AMD Radeon graphics cards for testing these two Linux proprietary driver releases and they were the Radeon HD 6950, Radeon HD 7950, Radeon R9 270X, and Radeon R9 290 graphics cards. A variety of OpenGL benchmarks and Linux games were used to test these two driver releases, including several Valve Source Engine games.
All of the benchmarking was handled in a fully standardized and repeatable manner using the open-source Phoronix Test Suite benchmarking software, where all tests are also run a minimum of three times for accuracy, etc.