Last week we reported that the open-source ATI Linux driver had picked up improved power management in the form of dynamic power management and power management profiles that can be defined by the end-user.

In part 1 of this series we learned how to measure how much power our systems are using, both hardware and software, and some tricks for reducing power usage without degrading performance. Today we're going to dive into the world of power management on laptops: ACPI, APM, hard disk spindowns, and spinups.

The default positioning of window-management buttons in Ubuntu 10.04 has generated a lot of controversy. But given the decreasing importance of these buttons in modern desktop environments, I'm left wondering if the issue is really so important.  In a year or two, after all, window titlebars may be a thing of the past.

Power management on computers has three parts: selecting devices that are more power-efficient, tuning your systems to run more efficiently, and configuring systems to use less power during periods of inactivity. Servers, desktop machines, and laptops usually need different power management schemes; there isn't a one-size-fits-all.

Move Ubuntu 10.04 Window Buttons from Left to Right with 1 Command: Perhaps the most annoying thing about Ubuntu 10.04 "Lucid Lynx" is the right-to-left window buttons (Minimize, Maximize and Close buttons) switch.

The following things might instead cause aggressive power management settings :

Two years ago Ubuntu began supporting LPIA, or the Low-Power Intel Architecture. LPIA is i386, but with different compile-time optimizations. LPIA was in use by the Ubuntu Mobile project with Intel's recent mobile CPUs supporting this lower-power architecture. Tests we carried out earlier this year at Phoronix showed Ubuntu's LPIA-based MID spin can conserve 10%+ power.

MiserWare MicroMiser is an intelligent software power management solution for x86 servers, laptops, and PCs running Linux. MicroMiser automatically optimizes a system to use energy more efficiently without compromising performance or availability.

Red Hat's Matthew Garrett has actively been working on improving power management with graphics processors via the various open-source X.Org drivers. There is quite a lot of work involved, but at the FOSDEM X.Org meeting he shared an update on his progress. In particular, Matthew is trying to conserve power with the GPU, memory, outputs, and displays.