If you wish to run AMD Llano Fusion APUs on the open-source driver, you must be building everything from source as the necessary Linux kernel / Mesa / DDX components do not have Llano in released form. With that said, this initial Llano support is likely buggy. The open-source Llano support could not be tested as we only had remote access to the A8-3500M system and could not monitor the process for OpenGL rendering issues or other problems along with it being more difficult to remotely handle system hangs and other problems. The open-source Llano Linux support will not be tested until we have our hands physically on the Llano systems.
AMD had produced on-time Ontario Fusion APU graphics support with Mesa / Gallium3D support, but it was initially quite buggy. It was only last month that the Ontario Fusion support had stabilized for us, but hopefully with Llano there will not be as many problems. By the time of Ubuntu 11.10 and Fedora 16 we will hopefully have reputable open-source Llano support in an "out of the box" manner and with decent performance. It will not be until the Radeon HD 8000 series where we may have a nice level of open-source support at launch. For now, early adopters will be best off with the proprietary Catalyst driver not only for the more mature support, but the proprietary driver also has much better power management abilities than the open-source Radeon DRM/KMS driver for mobile systems.
The other AMD Llano Linux article to be published later today has a lot more test results (for non-graphics areas) and a comparison to an Intel Atom platform, but in this article is just a quick graphics comparison to the previous-generation AMD Fusion E-350 APU. The system we had remote access to had the AMD A8-3500M APU with Radeon HD 6620G graphics, Compal PCL10, 4GB of system memory, and 32GB Intel X-25 Extreme SSD. Ubuntu 11.04 (x86_64) was tested with the Catalyst 11.4 (fglrx 8.84.60) graphics driver. The E-350 setup running within our labs had the ASUS E35M1-M PRO motherboard, 4GB of system memory, 64GB OCZ Vertex SSD, and the Radeon HD 6300 integrated graphics.
Testing was done via the Phoronix Test Suite.
With the OpenGL Nexuiz game, the AMD A8-3500M is more than twice as fast as the E-350 when both are using the Catalyst 11.4 proprietary Linux driver.