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

The Real Need For Nouveau Power Management

Michael Larabel

Published on 15 April 2010
Written by Michael Larabel
Page 3 of 3 - 5 Comments

Next up we looked at the video playback performance between Nouveau and the proprietary NVIDIA driver. We used the video-cpu-usage test profile within the Phoronix Test Suite, which uses MPlayer for full-screen 1080p H.264 playback. We tested out the Nouveau driver when using X-Video, the proprietary NVIDIA driver when using X-Video, and the NVIDIA driver when we were using VDPAU. VPAU is only available via NVIDIA's binary driver right now and this is the premiere video decoding API for Linux at this point. It is wonderful and can even allow HD video playback on a $20 CPU and $30 GPU as much of the video work is successfully moved over to the graphics processor.

Again, Nouveau really goes through the power. When comparing both drivers using X-Video, the Nouveau driver went through approximately 10% more power than the binary driver. However, when NVIDIA was using VDPAU, the notebook's power consumption dropped by 7%, or a 16% difference to the free software NVIDIA driver. In fact, the peak power consumption with the NVIDIA driver when using the Video Decode and Presentation API for Unix was even less than the Nouveau driver's average power consumption rate.

As the GPU is more taxed when using VDPAU than X-Video, PowerMizer does not down-clock the GPU core as you can see from the chart above. However, the power savings with VDPAU mostly come as the Intel Core 2 Duo is able to clock itself down to a lower frequency stepping via Enhanced Intel SpeedStep Technology.

As you can see from the chart above, the CPU usage is about the same when playing back the video file on the ThinkPad T61 between Nouveau and NVIDIA with X-Video, but with the NVIDIA driver you get greater power savings. When switching over to VDPAU though, the CPU usage zeros out and is of huge benefit over X-Video. There have been plans to bring VDPAU support to the Gallium3D driver architecture, but so far, it has not materialized.

The results in this article speak for themselves. It is rather unfortunate, but due to the lack of power management work within the Nouveau driver at this time, if you plan to use this free software driver on a mobile NVIDIA device, be prepared to have a much shorter battery life. This is unfortunate with more NVIDIA GPUs appearing in more notebooks and also NVIDIA's ION and forthcoming ION2 chipsets appearing in netbooks.

The Quadro NVS 140M is not even one of NVIDIA's most high-performance, power hungry mobile GPUs. Even still, compared to NVIDIA's official driver, the Nouveau driver burned through 28% more power when idling, 7% more power when gaming, and 10% more power with video playback (or 17% compared to VDPAU). This is all while the NVIDIA driver ran five and a half times faster with the OpenArena game and with VDPAU proved to be a superior solution for video playback. For those with NVIDIA graphics cards in desktops, the lack of proper power management support means greater power consumption, greater energy costs, and the GPU's fan running faster and more loudly. Hopefully in the coming months we will be able to report better news for power management in the Nouveau driver.

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. Preview: AMD's FX-9590 Eight-Core At Up To 5.0GHz On Linux
  2. Intel Launches The Core i7 5960X, Mighty Powerful Haswell-E CPUs
  3. AMD Radeon R9 290: Gallium3D vs. Catalyst Drivers
  4. AMD Radeon R9 290 Open-Source Driver Works, But Has A Ways To Go
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. Marek Lands Radeon Gallium3D HyperZ Improvements
  2. Mozilla Firefox 32 Surfaces With HTML5, Developer Changes
  3. Nouveau X.Org Driver Released With DRI3+Present, Maxwell, GLAMOR
  4. Microsoft & AMD Release C++ AMP Compiler With Linux Support
  5. AMD, Wine & Valve Dominated August For Linux Users
  6. Linux 3.17-rc3 Kernel Released Back On Schedule
  7. Lennart Poettering Talks Up His New Linux Vision That Involves Btrfs
  8. Mesa 10.3 RC2 Arrives Via Its New Release Manager
  9. Ubuntu 14.10's Lack Of X.Org Server 1.16 Gets Blamed On AMD
  10. MSI Motherboard BIOS Updating Remains A Pain For Linux Users
Latest Forum Discussions
  1. Lennart Poettering Talks Up His New Linux Vision That Involves Btrfs
  2. The dangers of Linux kernel development
  3. Updated and Optimized Ubuntu Free Graphics Drivers
  4. AMD Releases UVD Video Decode Support For R600 GPUs
  5. SSD seems slow
  6. Is laptop with Intel CPU and AMD dGPU worth buying considering especially AMD Enduro?
  7. Radeon HD5670 and Ubuntu 14.04
  8. Btrfs Gets Talked Up, Googler Encourages You To Try Btrfs