Computing@Thayer

Ever wonder how much power an average idle computer takes to run? A newer Dell Optiplex 745 with a 22″ LCD monitor, such as those in M210, consume 110 Watts just sitting there, not logged in with the screen saver on. When the monitor goes into power save mode, the consumption goes down to 70 Watts. When the computer itself goes into standby mode, power consumption plummets to just 2 Watts. Since most of the ~65 Thayer lab computers are idle most of the time, this presents an opportunity for saving a great deal of power.

Until now, computing services has set the monitors on our lab computers to go into power save mode, but the computers have remained idling, consuming around 70 Watts. Why? In Windows there is no off the shelf way to suspend a computer based on whether someone is logged in or not. We did not want machines going to sleep in the middle of the night just because the mouse had not been moved in an hour as that might interrupt a simulation running on the computer. To address this problem, we at computing services have written a script that puts the machine to sleep only when no one is logged on. This script is currently in testing on four computers in M210, and we hope to distribute it to our other lab computers in the near future. When a machine is sleeping, Its power light blinks, and the computer can be brought out of sleep mode by pressing the power button briefly. It takes about five seconds for the computer to wake up. If you have any questions of responses, please let us know!