Continuing on, the open-source driver was tested with the Radeon HD 6550D graphics on the Fusion A8-3850 in its stock configuration and then when enabling color tiling and disabling swap buffer waits. These two xorg.conf tweaks are known to increase the performance of the open-source driver, but aren't set appropriately by default since color tiling can still be problematic on some R600+ ASICs (it's only flipped on by default for the R300 through R500 parts) and stopping the swap buffer waits can lead to some possible screen tearing.
The performance of this A8-3850 setup was then compared to AMD's official Catalyst Linux driver. The Catalyst Linux driver release used was Catalyst 11.8 against this open-source driver stack from 24 August (Linux 3.1 Git, Mesa 7.12-devel git-cc9a891, and xf86-video-ati 6.14.99 Git).
Besides the AMD A8-3850 APU with Radeon HD 6550D graphics and the Sapphire Pure Platinum A75 motherboard, there was 8GB of DDR3-1800MHz RAM and a 60GB OCZ Vertex 2 SSD. The base OS was Ubuntu 11.04 x86_64 with the Unity 3.8.10 desktop, X.Org Server 1.10.1, GCC 4.5.2, LLVM 2.8, and an EXT4 file-system.