This morning a call for testing went out to try out the new pm-utils-powersave-policy package that should be making its way into the Lucid Lynx repository in time for the release of Ubuntu 10.04 LTS next month. This package offers up several fixes and new power savings features that should help those mobile users running Ubuntu 10.04 to prolong their battery life. We tested out this new package with a notebook and netbook to see how it changes the power game for Ubuntu 10.04 along with whether it's much of an improvement over the current Ubuntu 9.10 release.
As mentioned on the mailing list by Ubuntu developer Chase Douglas, the updated pm-utils-powersave-policy package brings several new features that are flipped on once the Ubuntu-powered system is running off battery power. These power saving measures include a ten-second audio codec power down, a one-minute console screen power-save timeout, a sixty second dirty page write-back timeout, disabling Wake-On-LAN (WOL) for Ethernet devices, enabling Serial ATA link power save mode, and enabling multi-thread and multi-core power save mode. Right now there is no audio codec power down on Lucid and the dirty page write-back timeout is set to 15 seconds, so there should be a measurable difference in power consumption even between the power performance of Ubuntu 10.04 right now and when the pm-utils and pm-utils-powersave-policy packages are updated. Edit: It turns out these updated packages will NOT be part of the Ubuntu 10.04 release but are being worked on for Ubuntu 10.10.
We used an Ubuntu 10.04 development snapshot with the Linux 2.6.32-16-generic kernel, GNOME 2.29.92, X.Org Server 1.7.5, xf86-video-nouveau 0.0.15, xf86-video-intel 2.9.1, and an EXT4 file-system. The upgrading of the packages from the Launchpad PPA took us from pm-utils 1.3.0~rc3-2git2 to 1.3.0~rc3-2git2~powersave1 and the pm-utils-powersave-policy package from 0.3 to 0.4~powersave1. We tested both set of packages and then compared them to a clean installation of Ubuntu 9.10 with the Linux 2.6.31-14-generic kernel, GNOME 2.28.1, X.Org Server 1.6.4, xf86-video-nv, xf86-video-intel 2.9.0, and also an EXT4 file-system. With our notebook testing, we used the 64-bit builds of each Ubuntu release while with the Atom netbook we were limited to using the 32-bit version.
We started out by running our power management tests on a Lenovo ThinkPad T61 notebook with an Intel Core 2 Duo T9300 "Penryn" processor clocked at 2.50GHz, 4GB of system memory, a 100GB Hitachi HTS72201 SATA HDD, and a NVIDIA Quadro NVS 140M graphics processor. All of our system monitoring was done through the Phoronix Test Suite, which is reading the battery consumption rate via ACPI through the Phodevi library. We started by monitoring the battery power consumption as the system idled for two minutes. The "Ubuntu 10.04 + New PM" results are with the Ubuntu 10.04 development snapshot and the upgraded pm-utils and pm-utils-powersave-policy packages from Chase Douglas.