The current implementation of powerd(8), which was introduced in FreeBSD 5.5, is very limited and only monitors the CPU's state. The powerd utility should also power down idle disk and other components to maximize power savings. The plan is to test a range of predictive algorithms and implement the best performer(s) into powerd. The "best performer" is defined as the algorithm that saves the most power while losing the least performance. http://www-flash.stanford.edu/~kinshuk/MCN95.ps presents a good sampling of algorithms that should be tried in powerd.

Additional power savings can be saved by monitoring the hard drive for inactivity and turning the drive off when no activity is detected for an extended period of time. Other devices will also be considered for power savings as the project moves foward.

[Update July 2, 2005] - I am designing the test suite that will be used to profile the various power scaling algorithms. In order to see the real performance characteristics of my work I need to be able to do statistical analysis for each step to see what is working and what is not. Bruno Ducrot and Nate Lawson (my mentors for this project) have suggested some workloads that I need to test for each algorithm.

powerd (last edited 2008-06-17 21:37:46 by localhost)