Switching off your computer at night

Kelter

Hi all,

I want to run a campaign at work to get people to switch off their computers over night. The benefits will be

1. Energy Saved by the computers
2. energy saved by the air conditioning system (particulatly now for the summer
3. Lifetimes of the computers


Now I can calculate/estimate the savings of the first 2, but I really want to find it writen somewhere that it is good for computers to switch them off one a day.

Anyone have a source?

Thanks

copacetic

Kelter wrote:

I really want to find it writen somewhere that it is good for computers to switch them off one a day.

Anyone have a source?

Thanks

I think you are more likely to find the opposite.

Kelter

I think your wrong. The little fans are working too hard

http://www.sustainable.org.nz/resource.asp?id=34

kmick

Some funny pictures to help your cause
http://files.webhost.ru/stuff/edf_ad.html
Main points from above
* A single computer uses 75% less energy each year if it’s turned off overnight and during the weekends
* Laptops use 75-90% less energy than a PC
* That a Cathode Ray Tube (CRT) monitor left on during the day and in standby mode during the night over a period of 5 years, costs the equivalent of a brand new flat screen monitor
* That flat screen monitors use only 1/3 the energy of a CRT monitor
* Myth No. 1 - switching off your computer regularly does not cause damage, contrary to a popular misconception that it does. If you’re going to be away from your desk for more than an hour or two, switch off your computer and definitely turn if off every night.
* Myth No. 2 – screen savers do not save energy.

copacetic

Kelter wrote:

I think your wrong. The little fans are working too hard

have a search around, there is a lot of stuff out there. In general the most stress is placed on the components at start up and shut down, doing this daily could lessen the lifetime of your machine.

The fans shouldn't be running much if the PC is in standby and them 'working too hard' doesn't really mean much in the computers lifetime.


edit: sorry your link was a bit late, I don't think linking a source like this is valid. Who are they to say what is and isn't true when they are on one side of the argument? 90% of the time a hardware component will fail at startup if it is going to fail.

Now fair enough if they said the risk is low and it isn't statistically significant but to say it isn't true that your PC is under more stress at power up is rubbish. Especially if you don't have surge protection.

Cabaal

Kelter wrote:

3. Lifetimes of the computers

There's a argument for leaving them on though as well, as you switch on a pc the solder expends and retracts due to cooling when your turning it off and heat when you turn it on, this potentially shortens the life of parts.

copacetic

reasonable link here on the saving in hibernate and sleep mode relative to power down mode:

http://www.microsoft.com/smallbusiness/resources/technology/hardware/do_you_need_to_turn_off_your_pc_at_night.mspx

kmick

copacetic wrote:

reasonable link here on the saving in hibernate and sleep mode relative to power down mode:

http://www.microsoft.com/smallbusiness/resources/technology/hardware/do_you_need_to_turn_off_your_pc_at_night.mspx

From that article
"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."

magicbastarder

kmick wrote:

* Myth No. 2 – screen savers do not save energy.

i would imagine that a computer showing a windows XP logo bouncing around the screen - and nothing else - would consume less power than a machine with a bright corner to corner display?

magicbastarder

don't forget that if your building has A/C, computers generating heat mean you have to run the A/C harder, costing more money...

copacetic

kmick wrote:

From that article
"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."

oh, i don't think there is any doubt that the power saving is well worth it to turn PCs off or have them in standby/hibernation.

No need to make up extra arguments that are dubious is my opinion.

leeroybrown

Kelter wrote:

I want to run a campaign at work to get people to switch off their computers over night. The benefits will be

1. Energy Saved by the computers
2. energy saved by the air conditioning system (particulatly now for the summer
3. Lifetimes of the computers

I'd like to be in a position to do this but the economics don't work out like this when I do them. The useful life of the computers in my office is such that (3) is pretty much irrelevant. The energy saving mentioned by (1) is pretty good. The air conditioning costs mentioned in (2) are valid for the summer but may well reverse during the winter. In my office things get a bit chilly if IT equipment is off for extended periods during winter.

In my case the amount of time I'd spend booting my computer, logging into various systems, closing everything down cleanly and powering things off is a pain and actually works out more expensive than the cost saving. Not very green though...

magicbastarder wrote:

i would imagine that a computer showing a windows XP logo bouncing around the screen - and nothing else - would consume less power than a machine with a bright corner to corner display?

The best screen saver is none. Set your power management to blank the screen and suspend the monitor instead. The power saved by having a dark screensaver is not that great.

Also, when people use screensavers they tend to go for bright flashy ones.

kmick wrote:

* Myth No. 1 - switching off your computer regularly does not cause damage, contrary to a popular misconception that it does. If you’re going to be away from your desk for more than an hour or two, switch off your computer and definitely turn if off every night.

This is only partially true. You don't do damage but older hard drives that spend long periods on have a tendency to suffer failures from a cold reboot. That said the economics don't justify leaving a PC on for this reason.

ednwireland

aah it used to be true pc pro had a feature on power saving etc

quote
Switching off will damage the PC or your data

No it won't. The boot and shutdown processes don't put any significant strain on the PSU or the major components, and modern hard disks are designed to park the head safely away from the surface of the platter when the drive is powered up or down.


http://www.pcpro.co.uk/features/101749/complete-guide-to-green-computing/page1.html

mind you i like the bit that once you get upto 24 inch lcd monitors your back to crt power consumption !

sorry to crib
"The three most power-hungry parts of a PC are the monitor, processor and graphics card. As a result, the energy demands of a top-of-the-range gaming PC can be much higher than a standard desktop. In our tests, the high-end Chillblast 8800GTX consumed a full 273W of power when running a 3D action game, whereas the Dell Dimension C521 consumed only 105W during the same 3D tests. Even when idle, the Chillblast used 183W compared to the Dell's 70W. The lesson? If you want to be environmentally friendly, don't buy a PC with a higher spec than necessary."
and
"Perhaps the most surprising results are those for energy consumed when the PCs and peripherals are turned off at the power button. Unbelievable as it may seem, your devices continue to draw power as long as they remain plugged in. The high-end Chillblast PC drew 3W of power when off, HP's C5180 inkjet took 6W, while many of the monitors took a residual watt or two. These may sound inconsequential, but when you consider that all your devices added together could consume 25W simply by being plugged in, over the course of a year they could eat up around 220kwh of power, which adds about £20 to your electricity bill. In other words, that £10 power strip that turns off all your peripherals with your computer would repay the investment within six months."
still havnt got to switching off at the plug though.

hope theres some useful info there

Kali

Kelter wrote:

Hi all,

I want to run a campaign at work to get people to switch off their computers over night. The benefits will be

1. Energy Saved by the computers
2. energy saved by the air conditioning system (particulatly now for the summer
3. Lifetimes of the computers

Rather than preach to the end-users who will find all this an unnecessary chore every evening and morning, talk to the IT administrators and management. It's fairly straightforward to put a shutdown script together for a set time every night (say 8pm) and similarly a WOL script for the following morning (say 7am)... this way no end-user complains, as long as they are aware of the situation and save any in-progress documents each evening (which should be standard practice anyway).

Put forward a trial run of ten twenty users perhaps to see how it works in practice, and then roll it out to the remaining users if there are no major issues.

Ken

leeroybrown

ednwireland wrote:

Switching off will damage the PC or your data

No it won't. The boot and shutdown processes don't put any significant strain on the PSU or the major components, and modern hard disks are designed to park the head safely away from the surface of the platter when the drive is powered up or down.

The effect I was referring to above has nothing to do with parking the heads. It's to do with older (older as in years of service) disks that typically run for long periods and are coming close to the end of their life that have to spin up while cold and fail. Not damage, just enough to tip them over the edge. As I said above, it's not a reason to not power off but it does happen.

Any kind of automated power off system in an office should be approached very carefully. If someone loses some work then it'll probably be their fault BUT when they go bleating to the employer that the auto power off caused €X worth of loss regardless of blame it mightn't take long to abandon.

2 stroke

Unless you have good surge protection, turn it off and plug it out, including the modem wire. My last pc was fried by a power surge through the phone line during a lightning storm. Modem, motherboard and processor fried.
Also computers with running 24/7 accumulate far more dust deposits inside the case which can lead to overheating, crashes ect.

bk

I work for a major US IT company that produces computer servers, etc.

I can tell you that from our extensive stats that most computer hardware failures occur during the reboot process.

We often find that servers that have been tipping along for many years with no problems suddenly suffer from hardware failure straight after you install a new patch that requires a reboot.

The reason is quiet obvious, the boot sequence of most computers is usually one of the most stressful things a computer does. Usually the fans rev up to their top speed and memory tests, etc are carried out. Also the machines goes through a major temperature change when going from off to on that can cause expansion (microscopic) that can cause all sorts of problems. This can often push hardware that was borderline to fail.

Now this mightn't be such a big deal for PC desktops, as typically in must enterprise environments they are replaced every three years, thus less likely to fail in that time. Also in any sort of decent enterprise setup, all the users data should be sitting on a directory server backed up by an administrator. So even if your desktop should fail, it should be possible to quickly and easily replace it with a new machine* with no loss of the users data.

* A good IT department will always have hot spares for immediate replacement.

However our advise for server machines is to avoid switching them off or rebooting them as much as possible.

So sorry, I'm afraid your third point is wrong, turning off machines every night won't extend the lifetime of your machines, it will in fact most likely decrease it.

Off course you should use the power saving features where ever possible.

BTW another interesting point, while LCD's typically use less power then equivalent sized CRT's. In my experience of enterprise environments, people usually buy larger LCD's when replacing CRT's (for instance going from 19" CRT's to 22" - 24" LCD's is fairly typical) which can often wipe out the energy saving of going from CRT to LCD

probe

The biggest power waster in the computer world is Microsoft with their default power options settings in Windows!

I set my laptop to switch off the display after 2 minutes of inactivity (whether using battery or mains) and the hard disks after around the same time. My system standby and hibernation settings are at 20 and 60 mins respectively.

If Windows shipped with shorter default power saving settings, the world would save zillions of GW of power and tonnes of CO2 and other pollutants.

.probe

2 stroke

If an item fails during a reboot, it was running on its last legs anyway, and would probably have failed during use eventualy, leading to lost data. Better to save data and shutdown regularly, rebooting can then be considered a system check as the fans rev up to their top speed and memory tests, etc are carried out.
Also, saying that computers tend to fail after a reboot is somewhat in error. What usualy happens in my experience is that a computer gives trouble and somebody tries a reboot before calling the IT guy.

copacetic

2 stroke wrote:

If an item fails during a reboot, it was running on its last legs anyway, and would probably have failed during use eventualy, leading to lost data. Better to save data and shutdown regularly, rebooting can then be considered a system check as the fans rev up to their top speed and memory tests, etc are carried out.
Also, saying that computers tend to fail after a reboot is somewhat in error. What usualy happens in my experience is that a computer gives trouble and somebody tries a reboot before calling the IT guy.

:eek:

bk

2 stroke wrote:

Also, saying that computers tend to fail after a reboot is somewhat in error. What usualy happens in my experience is that a computer gives trouble and somebody tries a reboot before calling the IT guy.

Not necessarily, I'm talking about very expensive Unix servers usually in big data farms behind locked doors, carefully administrated by experienced system administrators.

What happens is that the server needs to be rebooted after some security patch is installed and that causes it to fail.

My point is, turn off computers every night definitely puts extra strain on them and will reduce their life time.

I'm not saying that you shouldn't turn it off, if it is a cheap desktop PC that is backed up regularly and can be easily replaced. But you certainly can't use the third argument of switching off PC's extend their lifetime, because in truth it has the opposite effect.

2 stroke

If you want to extend the lifetime of pcs, find a way to stop them going obsolete.

magicbastarder

2 stroke wrote:

If you want to extend the lifetime of pcs, find a way to stop them going obsolete.

citrix?

2 stroke

Whaaaaa?

Bradidup

In the old days CIE used to keep their diesel locomotives running all night because it took too long to start them up in the morning, you could say the same about some computers.

magicbastarder

2 stroke wrote:

Whaaaaa?

it's allowing the backend servers to do all the work - all you need is a display box at the user end. you can have clients using hardware with no moving parts - basically just networking and video circuitry - which reduces the amount of electricity burnt at the client end. of course, you need beefier servers, but overall, it's less intensive.