Is PowerTop Still Useful For Extending Your Battery Life?
Three years ago Intel had released PowerTop, an open-source utility for Linux that would analyze how well your laptop was conserving power and would allow users to easily tune their system for maximum battery life via simple power optimizations. By simply running this utility, some users were able to significantly extend their battery life. However, is this utility still useful and needed with a modern Linux desktop? The most recent release of PowerTop (v1.11) was a year and a half ago, so we are seeing how well PowerTop is still able to reduce the power consumption of Intel notebooks/netbooks running Linux.
This testing is simple. We performed clean installations of an Ubuntu 10.10 daily snapshot on a Lenovo ThinkPad T60 notebook and a Samsung NC10 netbook. The Ubuntu 10.10 installation on each carried the Linux 2.6.35 kernel, GNOME 2.30.2 desktop, X.Org Server 1.8.2 RC2, xf86-video-radeon 6.13.0, xf86-video-intel 2.11.0, and an EXT4 file-system. The Lenovo ThinkPad T60 has an Intel Core Duo T2400 (1.83GHz, dual-core) CPU, 1GB of system memory, an 80GB Hitachi HTS541080G9SA00 SATA HDD, and an ATI Radeon Mobility X1400 GPU. The Samsung NC10 has the Intel Atom N270, 2GB of system memory, a 32GB OCZ Core SSD, and Intel 945G integrated graphics.
We first monitored the battery consumption rate for both the notebook and netbook after performing the clean install and then again immediately after following all of PowerTop's power tweaks. For both Intel computers the only recommendations on this clean Ubuntu 10.10 installation were enabling WiFi power savings, disabling the unused Bluetooth interface, enabling USB auto-suspend for non-input devices, and enabling HD audio power-save mode for the netbook. On both devices with and without the PowerTop recommendations, we monitored the power consumption rate when the systems were idling for five minutes and then again, under different workloads that included running OpenArena followed by immediately running the OpenMP-powered GraphicsMagick benchmark and then the PostMark disk benchmark. This testing was automated and battery results monitored via the Phoronix Test Suite.