Open-source code supporting the AMD Radeon HD 6000 "Northern Islands" GPU hardware has been available since January, but only in the past few days has this Linux code matured to the point of being stable and useful for testing. In this article are our first benchmarks of the AMD Northern Islands and Cayman graphics processors using the open-source Mesa Gallium3D driver and comparing its performance to AMD's proprietary Catalyst driver.
It was back during the Consumer Electronics Show in January that AMD released the initial Radeon HD 6000 series code for Linux users. This code provided KMS support and Mesa 3D support for both the classic Mesa driver and via Gallium3D, due to the similar architecture, this code was tacked onto the "R600" driver that now supports the Radeon HD 2000/3000/4000/5000/6000 series of ATI/AMD graphics cards. In February, AMD followed up by releasing Radeon HD 6900 "Cayman" series documentation and in early March they released Cayman KMS support, but it went without acceleration support. Finally, in May, AMD then released driver code to support acceleration on Cayman.
Sadly, up until now this code has been mostly busted whenever carrying out tests. Compiz would work in some of the configurations, but running any OpenGL games would quickly result in problems. Kernel mode-setting at least has been largely stable for the past several months for Northern Islands and Cayman hardware. Just two weeks ago, I was encountering hangs and other issues. This was with Radeon HD 6570, HD 6870, and HD 6950 graphics cards. Other Radeon HD 6000 series owners have encountered problems too.
Since the last time trying out the code in late June, several Radeon DRM fixes landed in the Linux 3.0 kernel (particularly with the 3.0-rc7 version). This week I then began receiving tweets to my Twitter account from users saying that the Radeon HD 6000 series on Gallium3D was finally working for them. When pulling the latest Linux kernel, Mesa, and xf86-video-ati DDX Git as of 12 July, everything was magically working!
The normal set of benchmarks run on Mesa were now successfully executing across the spectrum of Radeon HD 6000 series hardware at Phoronix. With the 12 July Git of the Linux 3.0 kernel, Mesa 7.12-devel, and xf86-video-ati, there is no longer any complaints in terms of crashes or show-stopping issues. The leading nuisance at this point would be the less than desirable level of power management support, but this isn't a Radeon HD 6000 series issue as it affects most generations of Radeon hardware. Particularly on the higher-end models, the lackluster power management causes increased power consumption for the system and the fan to operate at above-normal speeds. The Radeon HD 6870, for example, was screaming. The Sapphire Radeon HD 6870 is extremely quiet with its Vapor-X cooler, but constantly when using the open-source driver the fan noise was unbearable.