The May 2012 Open-Source Radeon Graphics Showdown
For the open-source Warsow game, the Catalyst driver is easily six to eight times (or more) faster than the open-source Radeon Linux driver code. Even with a Radeon HD 6770/6870, this Qfusion engine based game was not playable at 1920 x 1080 in the tested open-source Linux driver configurations.