Leave It On Or Turn It Off?

Over the last twenty years, I have been asked one question more than any other: “Should I leave my computer on all the time, or turn it off at the end of each day?” During that time, my answer has evolved from a long one to a very short one: “Yes.” When a client recovers from my initial response, I provide them with a more detailed answer explaining why I feel there is no single answer that works best for everyone.

In the “old days”, say ten or fifteen years ago, there was a plausible hardware-based reason to encourage users to leave their computers on all the time. Originally, computer circuit boards were very large and the expansion and contraction of components caused by heating up and cooling down could produce slight warping of these boards. The warping could potentially cause two significant problems. First, many computer chips were not soldered into place, but rather inserted into sockets that were then soldered to the boards. Unsoldered chips could work their way out of the sockets with the flexing of the board over time. Secondly, where solder was used to make connections, the warping could cause small fractures in the connections creating electrical failure points. Additionally, the initial surge of electricity when turning on a computer could result in excess voltages being sent to the delicate components. Add a hard drive into the mix and when you applied electricity, the discs’ rotational speed went from 0 to 3,600 rpm in under 2 seconds, placing a lot of strain on the moving parts.

Today, motherboards are much smaller; making them more rigid and warping is no longer an issue. Most if not all chips are now soldered into place. Power supplies are better designed to keep voltage and amperages within tolerable limits. Today’s hard drives are smaller and spin two to three times faster but they are engineered to tolerate the start up far better than ever before.

50% of my clients turn their computers off at the end of each day and the other 50% leave their computers on all the time. In the past 15 years, I have not seen any statistical difference in the failure rates of computers for either group. Hardware advances have improved the meantime between failures to the point where hard drives now come with 5-year warranties and every computer I sell comes with a 3-year warranty on internal components. The need to keep computers on 24 hours a day in order to maximize the life of the computer is simply passé.

So, without a hardware-based reason to guide us in making a choice, we are left with more subjective reasoning which basically falls into two categories: Economic and Convenience. The value of each of these two categories varies from person to person and therefore, must be considered on an individual basis.

From an Economic standpoint, let’s assume that a standard personal computer uses about 300 watts of electricity and electricity costs 10 cents per kilowatt-hour. At this rate, every 24 hours of operation will cost you 72 cents or $262.80 per year. When not in use, if you at least turn off your monitor (which uses the most electricity) and/or use the energy saving features of your computer, you can expect to cut your cost by 50 to 60 percent. Even then you will spend around $150 per year to leave your computer on all the time. Those who want to help save their pocketbook and/or the environment will probably want to turn off their computers when they are not using them. This does not mean you should turn off your computer every time you leave your desk, but shutting down your computer at the end of the day can indeed save money and reduces demand for electricity.

From a Convenience point of view, value is determined in a completely different way. For instance, after hours or while on the road, I often work on my office computer remotely. I have servers in my office that must run 24 hours per day to provide backup services each night. I simply detest having my virus scanning software running while I’m trying to work and prefer to have it run at 2:00 am when computer usage is low. I like coming to work each day with all of my email already downloaded to my inbox as soon as I arrive. The value of having my computer instantly available and accessible 24 hours per day far exceeds the economic cost of electricity.

One of the risks that you may encounter if you leave your computer on all the time is lightening and power failures. Lightening can send huge amounts of electricity surging through electrical circuits and telephone lines. These surges can turn your computer into an expensive paperweight very quickly. Regardless of whether you leave your computer on or turn it off, do not use your computer during severe weather that includes lightening. You might even consider unplugging it from the power and disconnecting any modem or network cables. This goes for cable/dsl modems and monitors as well.

On the other hand, power losses or brownouts where the voltage routinely drops below the standard 110-120 volts can damage computers just as easily as lightening, though it will take much longer. Using an Uninterruptible Power Supply (UPS) can reduce the potential for damage caused by either condition. A UPS protects against surges and conditions the incoming power to meet minimum voltages as necessary. Surge protectors are good, but if you want your computer to run 24 hours per day, consider getting a UPS battery backup; it’s good and cheap insurance.

Finally, if you decide to leave your computer on all the time, consider at least once per week, shutting the computer down completely, counting to 10 and then turning the computer back on. All computers benefit from clearing their memory registers and circuits from time to time. No matter what operating system you use, over time things can get confused.

In the end, you have to evaluate your own computer usage and needs when making this very personal decision. Many people feel their computer controls them, but in this one case you can be in total control and feel good about your decision either way.