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

PowerXpress Support Notebooks Under Linux

AMD

Published on 30 March 2011 08:04 PM EDT
Written by Michael Larabel in AMD
11 Comments

As mentioned this morning when AMD provided Canonical with a Catalyst 11.4 driver pre-release for proprietary Radeon / FirePro support under Ubuntu 11.04, there's more than just support for Linux 2.6.38 kernel and X.Org Server 1.10. This Linux driver update also provides support for AMD PowerXpress with dual-GPU notebooks.

PowerXpress is AMD's technology is part of ATI Hybrid Graphics and allows seamless switching between integrated graphics and discrete graphics for notebooks. It's designed to increase battery life for notebooks while still delivering maximum graphics performance when on AC power. This technology has been offered by AMD since 2008, but is finally coming to Linux.

With Catalyst 11.4, there's finally AMD PowerXpress support under Linux. While under Windows it's a seamless experience switching between the notebook's graphics processors, under Linux this is not the case. However, that's in large part due to existing limitations of the X.Org Server with not supporting hot-switching of GPUs and drivers. Fortunately, GPU hot-switching improvements may come this summer as part of GSoC, but don't expect to see any immediate advancements.

This PowerXpress support is similar to vga_switcheroo, which allows switching between the NVIDIA / Intel / AMD GPUs on the open-source drivers. This just came about a year ago in a rather rudimentary form, but it's working for the most part. This vga_switcheroo implementation also requires restarting the X.Org Server when switching between GPU/drivers.

With PowerXpress in the binary driver, not only does the server need to be restarted, but the OpenGL and GLX libraries need to be flipped out too. With vga_switcheroo on the open-source drivers, there is no switching needed since they all use the common Mesa libGL, but between Intel and AMD graphics with Catalyst, it requires flipping between Mesa and AMD's proprietary OpenGL implementation.

This switching also doesn't happen like it does under Windows when either connecting or disconnecting from an AC power source, but it must be initiated by the user.

When a user initiates the PowerXpress switch, the libglx file is switched automatically while the libGL library is switched when the X Server is restarted. This is done by two scripts shipping with the Catalyst driver called switchlibGL and switchlibglx. This switching is done just using symbolic links. Some distributions though may end up writing their own library file switcher so it complies with their packaging policies.

That's about it for the details I know right now. I don't have a PowerXpress-capable notebook around so am unable to verify its state and am just relying upon the information that was provided to me. It's also not known how it plays since the Intel graphics rely upon kernel mode-setting where as the Catalyst driver is not compatible with KMS.

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. NVIDIA GeForce GTX 970 Offers Great Linux Performance
  2. CompuLab Intense-PC2: An Excellent, Fanless, Mini PC Powered By Intel's i7 Haswell
  3. From The Atom 330 To Haswell ULT: Intel Linux Performance Benchmarks
  4. AMD Radeon R9 285 Tonga Performance On Linux
Latest Linux Articles
  1. Ubuntu 14.10 XMir System Compositor Benchmarks
  2. Btrfs RAID HDD Testing On Ubuntu Linux 14.10
  3. Ubuntu 14.10 Linux 32-bit vs. 64-bit Performance
  4. AMD Moves Forward With Unified Linux Driver Strategy, New Kernel Driver
Latest Linux News
  1. GTK+ 3.16 To Bring Several New Features
  2. Debian 8.0 Jessie Has Many Multimedia Improvements
  3. What Linux Benchmarks Would You Like To See Next?
  4. Open-Source, Linux Support For Corsair Link Devices Slowly Materializing
  5. Cairo-Dock 3.4 Shows A Lot Of Progress, Works Toward EGL/Wayland Support
  6. Mesa 10.4 Tentatively Planned For Early December
  7. SteamOS Update 145 Brings Compositor, Update Fixes
  8. GStreamer 2014 Conference Videos Posted: Wayland, HTML5, 3D
  9. Nouveau Now Supports DRI3 Without GLAMOR
  10. Features Of The Linux 3.18 Kernel
Latest Forum Discussions
  1. Updated and Optimized Ubuntu Free Graphics Drivers
  2. Linux hacker compares Solaris kernel code:
  3. HOPE: The Ease Of Python With The Speed Of C++
  4. Users/Developers Threatening Fork Of Debian GNU/Linux
  5. Ubuntu 16.04 Might Be The Distribution's Last 32-Bit Release
  6. AMD Releases UVD Video Decode Support For R600 GPUs
  7. Proof that strlcpy is un-needed
  8. xbox one tv tuner