Powering on/off

[absinthe]

I have a simple question...I've always wondered, is it better to leave your computer on all day and turn it off only at the end of the day, or turn it on when in use and off immediately after I'm done using it?

 

[SNGX1275]

Turn it on in the morning and off at night, or when you are finished for the day.
Reasons:
Sudden burst of electricity is bad for components.
Stopping and starting of spinning parts is arguably harder on them than leaving them running.
Warming up and cooling down of components should be minimized.

Many people I know leave their computers on ALL the time, only powering down for hardware changes or when the system locks up. Right now my computer has been on for 9 days 4 hours and 5 minutes.
Really there are only 4 reasons I can think of to turn it off if you have adequet cooling:
Saving electricity.
Leaving town.
Hardware change.
System lock up.

Of course if you are running a 9x based OS you might want to restart more often than every 9 days because 9x doesn't manage its RAM as well as the NT versions of Windows, meaning your performance will suffer after days of opening and closing programs.

 

[Rick]

There are two ways to look at this...

For the enviroment - Turn it off whenever you finish using it

For your wallet - Turn it off seldomly as possible

 

[Phantasm66]

I don't turn my computer off at all unless it is for reasons stated (hardware change, etc...) I DO ensure that I replace certain items (especially CPU fan) before they break, but other than that my machines especially the server runs 24/7.

 

[Per Hansson]

Of course if you live in an area where lighting is a problem you should always disconnect your computer from the wall if you are leaving the computer...

I made a post similar to this in the distributed computing thread:

About if this is good for your CPU or not:

Well, Imagine a car engine, when you drive short intervalls and lets it cool down inbetween that's when you have the most wear... What you want to do is drive as long stretches as possible to preserve the life of the car..

This complies to CPU's to, when they got hot and cool all the time they wear faster (worst case cenario is when you turn your computer off for the night!)

So if you run this program in the background it will use all unused clock cycles, meaning that if you start a program the performance will not be slowed down due to the client, it will only use the unused clock cyles then to...

This way your CPU will always keep a certain temperature, making it live longer... The same applies to the other components in your computer to like harddrives etc, but they are harder to preserve the life on... (don't turn off your comp is the best advice..)

 

[Mictlantecuhtli]

From Mikrosoft bCentral article:

Here are some consumer "myths" that are worth addressing:

Turning your PC off uses more energy than leaving it on. Not true. The small surge of power you use when turning it on — which varies per PC make and model — is still much smaller than the amount you use in keeping it on for lengthy periods.

Turning your PC on and off wears it out. Five or more years ago, there was something to this, but not today, say Hershberg and others. It used to be that PC hard disks did not automatically park their heads when shut off, and that frequent on/off cycling could damage the hard disks. Today's PCs are designed to handle
40,000 on/off cycles before a failure, and that's a number you likely won't reach during the computer's five-to-seven-year life span.

Screen savers save energy. Not true. Screen savers, at a minimum, can use 42 watts; those with 3D graphics can use as much as 114.5 watts, according to Don McCall, a Dell product marketing manager who does power measurement studies for the PC manufacturer. "It's absolutely wrong thinking that a screen saver will save energy," he says.

Your computer uses zero energy when "off." That's true only if it is unplugged. Otherwise, the PC utilizes "flea power," or about 2.3 watts, to maintain local-area network connectivity, among other things, McCall says. In "hibernate" mode, your PC uses the same 2.3 watts; in "sleep" mode, your PC uses about 3.1 watts.
Monitors do use zero energy when turned off.

Lab tests done by Dell show that a PC running Microsoft Office uses 42.7 watts, McCall says. If it runs continuously at that rate for 365 days, at 7 cents per kilowatt-hour, the power consumption costs would be $26.18 for the PC and $45.99 for a regular monitor, for a total of $72.17 for the workstation. Flat-panel monitors use less energy (22 watts when left on, 3.3 watts in "sleep" mode) than regular monitors (75 watts when left on, 5 watts in "sleep" mode), McCall says. So the same workstation with Microsoft Office running for a year would use $39.67 in power with a flat panel. Meanwhile, if a PC was kept in "sleep" mode for 20 hours, for every four hours "on," as Dell recommends, the annual energy costs per PC would total $16.17 with a regular monitor and $9.88 with a flat panel. Using "hibernate," the costs would be slightly cheaper.