"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. The first step is finding the power hogs on your systems, so today we'll learn how to measure hardware power usage. We'll also expose and rein in power-hog processes, and next week we'll learn some ways to get the most bang per watt on our Linux systems.
"The first lesson in power management on modern electronics is understanding that nothing is really off until you pull the plug. In my own personal computer lab I acquire a nice tan with the computers and room lights turned off. Routers, printers, surge protectors, backup power, speakers, and monitors all emit a radiant, friendly glow from their many LEDs. I have a running peeve with Hewlett-Packard over power switches on printers. My old HP6L doesn't even have a power switch. The newer Laserjet 3050 has a switch located on the back, way down at the bottom, requiring a long double-jointed arm to reach it. I'm waiting for HP to claim green creds so I can scoff at them..."
