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. The MSI X99S SLI PLUS Is Working & Running Well On Linux
  2. NVIDIA GeForce GTX 980: The Best GPU For Linux Gamers
  3. ROCCAT LUA: A Linux-Friendly Gaming Mouse
  4. Cheetah Mounts: The Affordable Way To Put Your TV On The Wall
Latest Linux Articles
  1. Preview: Radeon Gallium3D Performance For CS:GO On Linux
  2. XWayland Linux Gaming Performance With GNOME Wayland On Fedora 21
  3. EXT4/Btrfs/XFS/F2FS Benchmarks On Linux 3.17
  4. Fedora 21 Alpha First Impressions: It's Great
Latest Linux News
  1. Radeon DRM Gets New Information Ioctl Queries
  2. Mir 0.8 Works On Less ABI Breakage, Touchspots, Responsiveness
  3. CS:GO For Linux Gains Better Stability, Community Server Support
  4. NVIDIA Issues Updated 340.46 Long-Lived Driver Release
  5. KDE Plasma 5.1 Now In Beta
  6. Systemd & Debian Were Most Popular In September
  7. Microsoft Announces... Windows 10 With A Start Menu
  8. Borderlands 2 Launches On Steam For Linux
  9. Debian Jessie Might Get Rid Of The kFreeBSD Port
  10. Fedora Might Try A New Scheduling Strategy For Its Releases
Latest Forum Discussions
  1. Microsoft Announces... Windows 10 With A Start Menu
  2. NVIDIA Alerts Nouveau: They're Starting To Sign/Validate GPU Firmware Images
  3. Updated and Optimized Ubuntu Free Graphics Drivers
  4. Nero CD/DVD Burning Software On Linux Is Dead
  5. New Group Calls For Boycotting Systemd
  6. FSF Issues Statement On Shellshock Bash Vulnerability
  7. X.Org Women Outreach Program Only Turns Up Two Applicants So Far
  8. X.Org Is Looking For Some Female Help