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. MSI X99S SLI PLUS On Linux
  2. NVIDIA GeForce GTX 970 Offers Great Linux Performance
  3. CompuLab Intense-PC2: An Excellent, Fanless, Mini PC Powered By Intel's i7 Haswell
  4. From The Atom 330 To Haswell ULT: Intel Linux Performance Benchmarks
Latest Linux Articles
  1. Open-Source Radeon 2D Performance Is Better With Ubuntu 14.10
  2. RunAbove: A POWER8 Compute Cloud With Offerings Up To 176 Threads
  3. 6-Way Ubuntu 14.10 Linux Desktop Benchmarks
  4. Ubuntu 14.10 XMir System Compositor Benchmarks
Latest Linux News
  1. Sandusky Lee: Great Cabinets For Storing All Your Computer Gear
  2. Fedora 21 Beta & Final Release Slip Further
  3. Mesa 10.3.2 Has A Couple Bug-Fixes
  4. RadeonSI/R600g HyperZ Support Gets Turned Back On
  5. openSUSE Factory & Tumbleweed Are Merging
  6. More Fedora Delays: Fedora 21 Beta Slips
  7. Mono Brings C# To The Unreal Engine 4
  8. Coreboot Now Has Support For Intel Broadwell Hardware
  9. Enlightenment's EFL 1.12 Alpha Has Evas GL-DRM Engine, OpenGL ES 1.1 Support
  10. GTK+ Lands Experimental Backend For Mir Display Server
Latest Forum Discussions
  1. AMD Radeon VDPAU Video Performance With Gallium3D
  2. HOPE: The Ease Of Python With The Speed Of C++
  3. Updated and Optimized Ubuntu Free Graphics Drivers
  4. Ubuntu 16.04 Might Be The Distribution's Last 32-Bit Release
  5. Linux hacker compares Solaris kernel code:
  6. Advertisements On Phoronix
  7. Users/Developers Threatening Fork Of Debian GNU/Linux
  8. AMD Releases UVD Video Decode Support For R600 GPUs