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

Radeon DPM Is Fantastic For Power Use, Thermal Performance

Michael Larabel

Published on 30 July 2013
Written by Michael Larabel
Page 3 of 8 - 56 Comments

First up for testing is Xonotic, one of the most visually impressive and promising open-source first person shooter games.

When comparing the performance with and without Radeon DPM, the Radeon HD 6770 and HD 4890 graphics cards see no change in performance. This should be expected for all three graphics cards since their boot frequencies are their top-rated frequencies supported by their respective video BIOS -- i.e. Radeon DPM can't increase the frequencies any higher than they already were at, unless the open-source driver supported GPU overclocking. The HD 6870 interesting saw a very minor drop in frame-rate with DPM enabled.

The margin is quite small for how the Radeon HD 6870 performance was impacted with DPM enabled, plus the performance was already 200+ FPS, so I'm really not too worried. It's possible the performance could be negatively impacted if the Radeon DPM code is too conservative with its frequency scaling and takes too long to ramp up the clock frequencies, but that's hard to tell as there isn't any convenient sysfs/debugfs interface right now for being able to poll the core/memory frequencies in a real-time manner.

With this first test we see the GPU temperatures are indeed lower with dynamic power management enabled. The Radeon HD 6870 had an average GPU core temperature of 58.8 degrees (Celsius) without DPM and then the average went down to 52.3 degrees when re-clocking was enabled, since the frequencies/voltages were able to be reduced when the GPU wasn't under full load. The Radeon HD 6770 graphics card went from an average of 46.5 degrees to 43.4 degrees when DPM was enabled. The Radeon HD 4890 graphics card actually saw a rise in temperature from 65.7 to 68.8 degrees, but that may just be incidental.

Enabling Radeon DPM also leads to reduced power usage. The HD 6870 went from an average of 174 Watts for Xonotic to 130 Watts with DPM. The HD 6870 dropped from 131 Watts to 121 Watts. The Radeon HD 4890 went from 187 Watts to 178 Watts. These are the power consumption changes namely when the GPU is under load, but will be more noticeable when the GPU is idling. The GPU power consumption is still reduced under load due to PCI-E ASPM now being enabled and other changes in the Radeon DRM code.

While the frame-rates didn't change for the three graphics cards during testing, the lower power consumption led to noticeably higher performance-per-Watt values during testing. (This data is also auto-generated by the Phoronix Test Suite by setting the PERFORMANCE_PER_WATT=1 environment variable.)

Latest Linux Hardware Reviews
  1. Rosewill RS-MI-01: An Ultra Low-Cost Mini-ITX Chassis
  2. D-Link DCS-2330L HD Wireless Network Camera
  3. Gigabyte AM1M-S2H
  4. AMD's New Athlon/Semprons Give Old Phenom CPUs A Big Run For The Money
Latest Linux Articles
  1. Red Hat Enterprise Linux 7.0 RC Benchmarks
  2. AMD Catalyst 14.4 Brings Few Linux Performance Improvements
  3. The Performance Of Fedora 20 Updated
  4. Clang Fights GCC On AMD's Athlon AM1 APU With Jaguar Cores
Latest Linux News
  1. More Steam Linux Tests/Benchmarks Might Be Coming
  2. NVIDIA's Amazing Single-Board ARM Computer Might Be Delayed
  3. Fedora 21 To Get A Playground, New Features
  4. PC-BSD Is Developing Its Own Desktop Environment
  5. Valve Is Bringing VOGL To Windows & Working On Regression Tests
  6. Canonical Is Taking Over Linux 3.13 Kernel Maintenance
  7. Google Web Designer Is Now Natively Available On Linux
  8. Ubuntu 14.10 Is Codenamed The Utopic Unicorn
  9. Audacious 3.5 Lightweight Audio Player Released
  10. Steam Updated For Ubuntu 14.04 LTS, SteamOS
  11. DNF 0.5 Yum Replacement Now Supports Groups
  12. Red Hat Enterprise Linux 7.0 Is Looking Fantastic
Latest Forum Discussions
  1. HTPC-upgrade advice: AMD Richland A8-7600 or Kaveri A10-6700T ???
  2. The GNOME Foundation Is Running Short On Money
  3. What Else Would You Like To See On Phoronix This Spring?
  4. Linux Kernel Developers Fed Up With Ridiculous Bugs In Systemd
  5. The Most Amazing OpenGL Tech Demo In 64kb
  6. Announcing radeontop, a tool for viewing the GPU usage
  7. New card. Open source drivers only.
  8. Script for Fan Speed Control