To Sleep or Not to Sleep

October 2011
by Robin Wark

Does turning your computer off and on do more damage than leaving it running all of the time? Are you protected if you leave it running?

It is a good question: Should you turn your computer off?

While some computer users might not have strong feelings either way, others are firmly entrenched in their beliefs that one approach is better than the other. Each certainly has its merits. Let’s take a look at both.

Just let it sleep

Some people prefer to let their PC go to sleep rather than shutting it off. When they return to using their computer, it fires up way faster than booting it up. Plus, you do not have to spend time launching regularly used programs. It also allows them to continue working on files they were using before or reading a window they had previously opened.

According to various sources, sleep and hibernate modes do not take a lot of power. For example, a typical laptop PC uses one to two per cent of battery power per hour if it is in sleep mode.

Another advantage of not shutting your computer off is security updates and maintenance. Your anti-virus and anti-spyware databases, which keep you protected against emerging threats, can be updated at any hour of the day. Keeping your computer on also allows for system and network updates at any time. Some businesses prefer this. You can also set your security or PC optimization software to scan at a time when you don’t usually use your computer. A 4 a.m. scan can proceed without interfering with tasks you are doing.

There are three basic kind of power saving modes that are often confused for each other. Sleep mode saves power and lets you resume your work, with full-power, within seconds. It can be described like pressing “pause” on your DVD player or PVR. Sleep puts your files and settings in memory and draws a small amount of power.

Hibernation is a power-saving feature primarily for laptops. It puts your open documents and programs on your hard disk and turns off your computer. The next time you boot up, the programs and documents are restored.

The hybrid sleep function is primarily for desktop computers. It puts your open documents and programs in memory and on your hard disk and then enters a low-power state. This means you can quickly resume work when needed.

To have your PC sleep or hibernate, click the Start button, click the arrow next to Shut down and make your choice. To use hybrid sleep:

  1. Click the Start button, Control Panel, System and Maintenance (or System and Security, depending on Windows version), and then Power Options.

  2. On the Select a power plan page, click Change plan settings next to the selected plan.
  3. On the Change settings for the plan page, click Change advanced power settings.
  4. In the Advanced settings tab, expand Sleep, expand Allow hybrid sleep, and then do one of the following:

    • If you are using a mobile PC, click On battery or Plugged in (or both), click the arrow, and then click On.
    • If you are using a desktop computer, click Setting, click the arrow, and then click On
  5. Click OK, and then click Save changes.

Shut it off at night

There has long been a thought that turning your computer off and on does more damage than just letting it run. The United States Department of Energy’s website on Energy Efficiency and Renewable Energy (EERE) says that is no longer a concern:

”Most PCs reach the end of their ‘useful’ life due to advances in technology long before the effects of being switched on and off multiple times have a negative impact on their service life. The less time a PC is on, the longer it will ‘last.’”

The website also reminds that PCs produce heat. By turning them off, you can reduce “building cooling loads.”

A compromise?

There are definite benefits to shutting off your PC or letting it sleep, hibernate or hybrid sleep. If you do not strong prefer one or the other, perhaps a compromise is in order:

  • If you have a desktop computer, consider turning off the monitor if you aren’t going to use it for more than 20 minutes. That allows you to save energy but also quickly get back to work.
  • Or you could set your computer to go into Sleep mode after 15 minutes of inactivity.
  • You might want to consider shutting off your computer if you are not going to use it for 2 hours or just turning it off at night.
  • The TreeHugger.com website suggests using powerstrips for your computer and hardware devices. This way, after you turn off your computer and devices separately, you can just flip a switch at night and stop power from being used by these devices.

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