Power Management: ATI Catalyst vs. Open-Source ATI Driver

Yesterday we broke the news that AMD will stop supporting the R300-500 GPUs in the Catalyst driver. There have been well over one hundred posts in the Phoronix Forums from ATI customers upset with this decision, but fortunately, there is first-rate open-source support available. AMD continues to release documentation and code while the X.Org development community has been hard at work on the xf86-video-ati and xf86-video-radeonhd drivers along with Mesa and Gallium3D components. The main problem though is the open-source stack -- at this time -- providing poor gaming performance, but power management can also be a problem. In yesterday's article we provided some R500 comparative 2D and OpenGL benchmarks, but in this article are some power management results comparing the Catalyst 9.2 driver to the xf86-video-ati driver.

For this testing we used a Lenovo ThinkPad T60 notebook with an Intel Core Duo T2400 processor, an Intel 945GM Chipset, 80GB HTS541080G9SA00 SATA HDD, 1GB of system memory, 1400 x 1050 display, and for its graphics is an ATI Radeon Mobility X1400 with 128MB of video memory. The Linux operating system we used was Ubuntu 8.10 with the Linux 2.6.27 kernel, X Server 1.5.2, xf86-video-ati 6.9.0, Mesa 7.2, GCC 4.3.2, and the EXT3 file-system. We had compared the performance using the stock open-source ATI packages to Catalyst 9.2.

In addition to being able to manage the execution of over 90 tests in an automated, reproducible, and standardized manner, the Phoronix Test Suite is also capable of monitoring system sensors across a variety of subsystems -- among them is ACPI support for reading the battery consumption rate and integrated thermal sensors. We paid attention to the battery power consumption while the system idled and while running the Tremulous (ioquake3 engine) game. This was done under the open-source ATI stack and then with the proprietary Catalyst driver.

For this testing, Ubuntu and the display drivers were left in their stock configuration. Enhanced Intel SpeedStep Technology was also enabled on this notebook. There is a branch of the xf86-video-ati driver that provides basic R500 PowerPlay support, but for this testing we are focusing solely on what the "out of the box" experience is with Ubuntu Linux and ATI graphics.

On the next page are our recorded numbers as the Lenovo ThinkPad T60 was running off a 9-cell Lithium Ion battery.