1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking.org

RadeonHD Driver Power Management Improves

AMD

Published on 24 July 2009 03:17 PM EDT
Written by Michael Larabel in AMD
10 Comments

While we just shared that there are now patches available that introduce HDMI audio support for the xf86-video-ati driver, the RadeonHD driver has picked up improvements for power management, an area where previously the xf86-video-ati driver was in a better position. Novell's Matthias Hopf added some power management support for an area of the AtomBIOS that he had reverse engineered, after AMD hadn't provided any public documentation on the matter.

With this new power management code, the xf86-video-radeonhd driver will attempt to read voltage and clock information from the AtomBIOS and then try to figure out the different combinations of voltages and frequencies that will work without leaving the card in a non-functioning state. There is code in place with the RadeonHD driver for controlling the engine clock, memory clock, and VDDC voltage, but right now it's just implemented for making engine clock adjustments.

Not only is it difficult to compute the combinations in which the clocks and voltages can run at in a stable manner, but then applying the changes is also difficult. In order to change the GPU clock, the GPU must first be idling. Similarly, there cannot be any GPU memory accesses performed when the memory clock is about to be changed. Additionally, everything must be idling when the voltage changes. As a result, this work is still far from complete and there is a lot of testing and verification work that needs to go on.

Meanwhile, work has been going into the competing xf86-video-ati driver for the past several months to down-clock the GPU, decrease the PCI Express bandwidth, and carry out other functions in order to conserve small amounts of power.

For those interested in the RadeonHD power management work that is going on, read this mailing list entry.

About The Author
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via and or contacted via .
Latest Linux Hardware Reviews
  1. Intel Launches The Core i7 5960X, Mighty Powerful Haswell-E CPUs
  2. AMD Radeon R9 290: Gallium3D vs. Catalyst Drivers
  3. AMD Radeon R9 290 Open-Source Driver Works, But Has A Ways To Go
  4. Trying The Configurable 45 Watt TDP With AMD's A10-7800 / A6-7400K
Latest Linux Articles
  1. How Intel Graphics On Linux Compare To Open-Source AMD/NVIDIA Drivers
  2. The Fastest NVIDIA GPUs For Open-Source Nouveau With Steam Linux Gaming
  3. Testing For The Latest Linux Kernel Power Regression
  4. The Most Energy Efficient Radeon GPU For AMD Linux Gaming
Latest Linux News
  1. AMD Steppe Eagle Flys To Coreboot
  2. Intel Beignet Is Working Out Surprisingly Well For OpenCL On Linux
  3. Coreboot Adds Lenovo X220 With Native Sandy Bridge Support
  4. Canonical Has Yet To Land X.Org Server 1.16 For Ubuntu 14.10
  5. Imagination Launches A MIPS Development Board
  6. Getting Involved With The New Raspberry Pi Graphics Driver
  7. A New AMD Catalyst Linux Driver Unofficially Surfaces
  8. LibreOffice Ported To 64-bit ARM (AArch64)
  9. Enlightenment E19 RC3 Shows Off The New Wayland Compositor
  10. Metro Redux Is Going To Require OpenGL 4.x On Linux
Latest Forum Discussions
  1. Btrfs Gets Talked Up, Googler Encourages You To Try Btrfs
  2. Updated graphics drivers for Ubuntu 12.04 Precise LTS
  3. Catalyst 14.201.1008
  4. It's Now Possible To Play Netflix Natively On Linux Without Wine Plug-Ins
  5. Users defect to Linux as OpenBSD removes Lynx from base system
  6. Updated and Optimized Ubuntu Free Graphics Drivers
  7. Canonical Joined The Khronos Group To Help Mir/Wayland Drivers
  8. Radeon HD5670 and Ubuntu 14.04