AMD Llano Graphics / Radeon HD 6620G On Linux
AMD's next-generation "Llano" Fusion APUs are launching today. Llano is a very nice upgrade over the current-generation 40nm Brazos hardware as talked about in another Phoronix article to be published in the next couple of hours, but in this article is a look at the graphics in Llano. Here's the first Linux look at the Llano graphics support and performance for the Radeon HD 6620G as found with the AMD A8-3500M Fusion APU.
With the A-series Fusion technology we at least have launch-day Linux performance numbers this time around compared to the AMD Fusion E-350 Linux benchmarks coming months after the launch when we went out to purchase the hardware directly. With the AMD Llano Linux benchmarks, however, it is still not due to AMD's interest towards Linux results. AMD's Legacy (CPU) side hasn't sent us out hardware in a very long time, even with all of the AMD Linux articles published on Phoronix that are pretty much on a daily basis due to various open and closed-source AMD Linux driver advancements. There is also no shortage of AMD Linux developers within our forums, but I digress. One AMD employee did send over beer at least (if it was from their Dresden team though rather than Austin it would be a better consolation prize). To deliver these A8-3500M Linux benchmarks today, we had to obtain remote SSH access to a Llano system from an independent party.
The mobile system we had remote access to had an AMD A8-3500M, which packs an integrated Radeon HD 6620G graphics processor. This Redwood-class graphics processor has a 444MHz GPU clock speed with UVD3 support, Microsoft DirectX 11 / Shader Model 5.0 support, and 400 Radeon compute cores. When all drivers are working correctly, the Llano Fusion graphics should be superior to Intel's rather decent Sandy Bridge "HD 3000" integrated graphics and run at a speed comparable to the Mobility Radeon HD 4650 GPU.
In terms of Catalyst Linux driver support, I have not been told (or manually checked) the bounds of the hardware support. Catalyst 11.4 is what was used for this testing, which is the April release stream and is what's found in the Ubuntu 11.04 "Natty Narwhal" repository and is what most users will probably choose. The Catalyst 11.4 Linux driver has support for X.Org Server 1.10 and the Linux 2.6.38 kernel as found in most modern Linux desktops. At least the initial Llano support has hit here so users can easily enable proprietary support if they so choose. Had there not been Llano support in the 11.4 release stream, there would be many angry Linux users similar to the initial Intel "Sandy Bridge" Linux enablement, but at least with a proprietary driver stack it's much easier to manually install a new release. With Catalyst 11.4, everything appears to work appropriately, but of course, I would always recommend using the latest monthly driver release for the best support and mature feature-set.
In terms of open-source driver support for the Llano APUs, as recently reported on Phoronix, there is some level of support as talked about on Phoronix recently. The Linux 3.0 kernel contains some Radeon DisplayPort 1.2 changes that are necessary for supporting Llano. Two weeks ago AMD did release Radeon DRM/KMS support for Llano. That same day they also released Mesa and Gallium3D support for Llano along with the initial enablement for the xf86-video-ati DDX driver. This means that there is initial open-source Llano graphics support available to Linux users, but it's not found "out of the box" in any Linux distributions at this time.