Regular visitors to Greener House know that if it has a plug, I like to shut it down completely at night. So I was disappointed to enter my office this morning and hear that my desktop computer hard-drive had been humming all night long. The monitor had switched itself off, but the PC had probably been eating through about a hundred watts for the past 14 hours. The irony is that I had just been reading the night before about PC power consumption and suggestions for ways to reduce it. Leaving the computer on through the night was not one of those suggestions.So I took this as a hint to stop relying on my own good habits and set the computer up to go to sleep even if I’m too dopey to put it to bed. I’m used to computers going to sleep on their own because I mostly work on a laptop. (Laptops use far less power than desktops.) I had assumed that my PC eventually went into standby itself. But like most desktop PC users, I had never set Windows to go into standby if idle. The U.S. Environmental Protection Agency has found that sleep mode is enabled on only about 5 percent of commercially used PCs in the States.
The process is so simple it’s hard to believe it comes from Microsoft. In Windows XP, click Start>Control Panel>Power Options. There, I discovered that my desktop was set—probably at the factory—to turn off the hard disks “Never” and standby or hibernate “Never.” I changed these options to turn the monitor off after 15 minutes, turn off the hard-drive and go into standby after 30 minutes and hibernate after 2 hours.
Standby spins down the hard-drive and puts the machine into power saving mode, but maintains power to your memory so you don’t loose your work and your documents and programs remain open. When a machine hibernates, it saves whatever you have been working on and shuts down more-or-less completely. When awoken—by quickly pressing the power button on my PC—it will return to the state in which you left it, but this takes longer than reviving from standby. On my machine, waking up the CRT monitor alone takes about 7 seconds, waking up the computer from standby takes 12 seconds and from hibernation takes 25 seconds.
At this point you may be starting to remember the advice about computers you once heard from a friend of a friend of a friend. Perhaps you heard that computers use hardly any electricity when they are awake but idle. Or that when the monitor switches into screensaver mode it uses less power. Perhaps the story you heard was that starting up a computer takes more energy than leaving it on, or that hard-drives last longer if you leave them spinning all night.
They are all myths. You will find them well debunked on Michael Bluejay’s page on computers within his excellent website devoted to saving electricity. Walt Mossberg, the personal technology guru of the Wall Street Journal, addresses the last myth here.
Screensavers won’t help you reduce power consumption; the computer and monitor are still working. Screensavers save screens, not electricity. Idle computers use almost as much energy as when doing light work, such as word processing. Starting a computer takes no more power than using a computer, and hard-drives running 24/7 die sooner, not later.If you are about to buy a computer, I recommend Mike Chin’s thorough article Choose an Energy Efficient Computer. His general recommendations are laptops, iMacs and LCD monitors, but he also has specific recommendations for PC processors. Replacing a CRT (Cathode Ray Tube) monitor with an LCD model will instantly cut consumption from about 80 watts to approximately 35 watts for a 17-inch model.The most energy efficient computer is one that is off, however, so if you find that a chore, here are some Windows XP shortcuts to make it easier. If you have several windows open, hold down Alt and press F4 as many times as required to close each window and one more time to bring up the Windows shut-down box. Then press the letter U and the PC will turn off safely. If you already have all programs closed, pressing Start-U-U on the keyboard is even faster.
My new power settings are just a backup. I still plan to turn off my PC completely at night—when I remember.