Leave Computers On or Off Overnight???

By request, I've searched and researched the question as to whether to leave the computers on or turn them off when not in use. I searched my personal archives, the internet, and interrogated fellow computer repair people, and engineer, and even stumbled upon a thesis from MIT. A strong case can be made for either side of the issue so please read on and decide for yourself. But don't worry, I won't leave you hanging. I will also let you know what I do with my computers.

Arguments for turning the computers off:
Old school logic would have you turn off your computer when not in use. Computers used to consume $10.00 of electricity each month. That alone would move me to click the off switch. In addition, the bearings on cooling fans and hard drives were not so good and would wear out in about a years worth of continuous running. Let's see 8 hours of work and 16 hours of running idle - Old school says "Turn It Off!"

Home computers were used differently back then too. Dad did the check-book and played pong or pac-man. Mom played a little solitaire and that was it. The computer was used an hour or so during the evening, then turned off until the next time.

Electrical Theory: The electrical theory is that during operation a piece of equipment is subjected to more surges in power than the initial surge whilst turning on and off is worth, which means over time more damage is done with the power on. Also, electrical parts wear out due to constant heat. It's more of a high mileage theory, with the analogy, "Light bulbs are rated for so many hours of use, and once they're used, the bulb will blow".

Conspiracy Theory: Electrical power companies have conspired to convince people to leave their equipment on to increase profitability. (Believe it or not, most of the folks I asked the suggested turning off the computer when not in use, came up with this reason first, and, frankly, it made me question everything else they said).

Arguments for leaving the computers on:
Power and Torque: At the instant that an electrical device is turned on or off to a power source, there is an electrical burst of energy comparable to a mechanical "jerk\" The rate of change is instantaneous and infinite. This electrical "jerk", surge, or spike, for an instantaneous moment, brings voltages much much much higher than the 5 or 12 volts normally used to power the devices inside your computer.

Notable as well, motors such as the electrical motors in the hard drives, floppy drives, CD/DVD, and fans take a big shock called torque when it goes from running at 7200 rpms to a dead stop. This is repeated when the switch is turned on and these devices go from 0 rpm to 7200 rpm.

All of this means that at the moment the machine is turned on, an incredible amount of current is necessary to get things moving, and the mechanical torque and electrical surge is at it's highest, usually instantaneously higher than the tolerances of the equipment. This is the point where equipment usually fails, as it is the greatest amount of instantaneous load that can be put on the equipment.

Case and point, A light bulb never blows when it's already on, it only blows when it is turned on. Same is usually true with a computer.
I personally keep my computers on 24/7 for several reasons:

1.    I don't believe in conspiracy theories.

2.    Computers draw much less electricity than in yesteryear. A typical DuelPro 2 gigs of ram, 320 gig drive, CD/DVD will cost about $30.00 a year to leave on ($2.50 a month – 8 cents a day).

3.    The toque / spike thing came from an engineer that I trust. It's real and is not impacted or improved by a surge protector or battery backup.

4.    Surge protectors or Battery Backups (UPS), particularly those that run the computer off of the battery, nearly eliminates spikes and surges whilst running your computer. (However, they do nothing to improve spike and torque issues whilst turning the computer on and off.)

5.    Microsoft Updates can occur at 3:00am and be complete by the time you wake up and start using your computer at 6:00am (some of these take an hour or more to complete)

6.    Anti-Virus Updates and scans can occur during the night rather than when you are trying to boot your computer to quickly see your checking account balance.

OK!  I spilled the beans! I recommend leaving the computer on 24/7, as well as modems, routers, and firewalls.

However, I do turn off printers, monitors, audio equipment, cameras, and most other peripherals connected to the computer. Why?

1.    Many of these devices such as monitors use more electricity than the computer (savings)

2.    Most peripheral devices turn on and off instantly no wait.

3.    Most peripheral are tougher than computers and can take the abuse

4.    Most peripheral are no subject to Microsoft Updates and Anti-Virus Updates

5.    Most peripheral are very inexpensive to replace VS a computer

http://active-technologies.com/content/leave-computers-or-overnight