ATI PowerPlay Reanalyzed
Last year we had taken an in-depth look at ATI's PowerPlay technology upon the support within the Linux fglrx display drivers. Now that Fedora Core 5 has been out for some time, and there have been quite a few monthly releases since that point, we are now back today as we re-examine ATI's PowerPlay using once again the Mobility RADEON X300. In this examination, we will also be using additional benchmarks beyond what was done in our original benchmarking fiesta, and we will be examining its power consumption when using the AC adapter and simply not the battery. Continue as we examine this technology once more, and get a better understanding if this implementation is for all mobile users.
For those not familiar with ATI PowerPlay, it has been available within the Windows CATALYST drivers for some time; however, it was not implemented within the Linux fglrx drivers until last year with v8.19.10 release. PowerPlay allows the user to manually specify specific "power-states" at which the graphics card can operate. While this will slow down the graphical performance, it can greatly increase the longevity of the battery-life, which is critical for a majority of mobile users. These various power-states control the GPU clock/memory frequencies and voltages. As was the conclusion in our first PowerPlay article, the software implementation had done its job of greatly extending the battery-life -- in upwards of 25%. There was a 3D performance downfall; however, for desktop usage the side-effects were minimal. While it was not a quantitative focus in our previous article, the heat generated had also decreased once the technology was enabled.
Most recently, ATI has even altered the installer when using the Ubuntu and SuSE packages, it has automatic detection for notebook users and can automatically adjust the PowerPlay power-states whether the battery or AC adapter powers the device. This dynamic PowerPlay script may ship with support for additional distributions in an upcoming release. However, this script can be obtained from extracting the ATI installer contents and retrieving the ati-powermode.sh from the packages. This ATI power script does require acpid.
As was done with the original article, the notebook used was a base IBM/Lenovo ThinkPad R52. The specifications for this notebook include an Intel Pentium M 750 (1.86GHz), i915PM + ICH-6M motherboard, Toshiba Slim MK1032GAX 100GB ATA-6 16MB HDD, 2 x 1GB OCZ DDR2-533, DVD+/-RW Drive, Intel PRO/Wireless 2915ABG, and ATI Mobility RADEON X300 graphics with 64MB dedicated video memory. To ensure accuracy, Intel's Enhanced SpeedStep Technology was set to run at 1.87GHz, rather than dynamically clocking the CPU. For this article, the mobile solution was running Fedora Core 5 (i686) with the 2.6.16-1.2096_FC5 kernel, GCC v4.1.0, X.Org v7.0.0, and GNOME v2.14.0. The proprietary ATI fglrx v8.24.8 display drivers were used. As mentioned in past Phoronix articles, the present ATI installer does not fair well when it comes to stock Fedora Core 5 compatibility. We had also mentioned that ATI intends on adapting some changes to the installer within a few releases, which should result in improved FC5 detection. In the mean time, the Livna repository is a viable source for attaining the ATI fglrx packages.