Some time ago, CSAIL bought me a new laptop to replace my aging, but still quite capable, ThinkPad T40p. The new laptop, a ThinkPad T60p, is basically a straight upgrade from the old one. Same physical size, but "bigger" in the abstract sense. Except when it comes to battery life, where it's clearly worse than the T40p. I live with this for almost a year until stumbling across LessWatts.org, an Intel-run site with a bunch of information about power management and tweaks in Linux.

Since my goal is to make the T60p act more like the T40p in terms of power consumption, my first task was to quantify the actual difference between the two, so I don't need to rely on feel. Since both machines run Debian stable (etch) with the same kernel, (and thus the same power management code), this was fairly easy. Here's a graph comparing the power consumption of the two machines, in very similar configurations, sitting entirely idle:

The graph shows that, without doing anything unusual to minimize power consumption, the T60p uses approximately twice the power of the T40p.

So now it's time to start actually trying to do something about what seems to me to be a horribly inneficient use of power. I'll start by switching to a newer Linux kernel supporting dynticks, being more aggressive in the use of wireless network device power management, and the power saving CPU scheduler options. Since my laptop contains and Intel AHCI SATA controller, I can also experiement with SATA power management, which appears to have the most potential for dramatically reducing power consumption. I'll get to that when I have some idea about the affects of the first few tweaks.