Greener Computing
Posted on September 25, 2007
Filed Under Business Computing, Windows |
One of the perennial questions computer service people are asked is “should I leave my computer running or shut it off?” The answer has never been clear, and there have traditionally been two trains of thought a) leave the computer on as constant powering up and down of components can cause them to fail sooner and b) turn the computer off when not in use as components wear out with constant use.
Personally, I’ve in the past sat on the fence on the issue and took the stance that fits both views; power down when not in use for long periods – such as during the night – and leave the computer running at other times. There has never really been much argument that servers and network equipment, like routers and switches, should be left running at all times.
Different computers use different amounts of energy depending on the power supply, number of drives, fans, peripheral components, and so and so on. One thing that is clear though is that a PC will draw more power as it’s booting (starting up) as it needs to spin up drives, fans, and the like. A rough guide to PC power consumption can be found at http://michaelbluejay.com/electricity/computers.html.
There are of course a number of methods to conserve power and many of them come from the notebook world where conserving battery power is a must. The simplest method is to shut down when the computer isn’t in use and I’ve modified my prior dissertation to meet the needs of those most concerned with power consumption; shut it down any time you won’t be using it for a couple of hours.
Unfortunately that can sometimes be a serious pain in the neck. Some computers take an inordinate amount of time to boot up and it isn’t always practical to close all of your open programs only to boot up and open them again in a few hours. That’s where built-in power management can help a great deal. Please note: we’re talking Windows here; your mileage may vary with other operating systems.
If getting back to work quickly without waiting for a reboot is a driving concern, “Sleep” mode is probably your best bet. In sleep mode (standby on XP) hard drives are powered down, the monitor is shut off, and power is only used to keep the contents of RAM memory intact.
The beauty of sleep mode is that with the contents of RAM memory intact, all that’s needed to get the computer running again is to spin up the hard drive, turn on the monitor, and power up the rest of the system. When you press the power button while in sleep mode, the computer starts up in a fraction of the time it would were it shut down completely. The only drawback is that power is used to keep the contents of RAM memory intact. For real power savings you need “Hibernate”.
In hibernate mode the contents of RAM memory are copied to a special file on the hard drive. Because the hard drive can preserve data even when the computer is off, the system can be completely powered down and when it starts back up, it is in the same state you left it when you originally hibernated with open programs running and all. The drawback to hibernate is that the system is slower to shutdown because RAM memory must be copied to the hard drive, and slower to start up again because RAM memory must be retrieved from the hard drive.
While sleep and hibernate were originally designed to address battery life in notebooks, they work equally as well to conserve energy on a desktop computer. Both are shutdown options in XP and are available on the shutdown menu in Vista.
If neither of these options work for you, consider simply turning off your monitor when you’re away from the computer for any length of time. There are no drawbacks to shutting off the monitor and it can save a good deal of energy.
Last, if you have more than one server on your network, an excellent way to conserve energy is to employ virtualization technology that will let you run multiple server operating systems on one physical server. More on that later though!
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