How much power does a computer use on all the time?

[xequence]

How much power does a computer use when it is on all the time?

Basically my parents dont like me leaving my computer on all night to do stuff. But I tell them that the ammount of power it uses is insignifigant...

Anyone know how much power it uses? :P

[matthew]

First answer: it depends on the processor, whether the monitor is on or off, and what the computer is doing. Are you just downloading something (linux distros, right?) or are you doing massive 3D rendering? More data is needed for a more precise answer.

Short answer: the amount of electricity being used leaving your computer overnight is likely minimal and not worth worrying about just like you told your parents.

[Jedeye]

Good question... I have been wondering that myself. I found this http://michaelbluejay.com/electricity/computers.html


Computers account for only a fraction of worldwide electrical use, even with the burgeoning Internet. Air conditioning, lighting, and refrigeration account for a LOT more. The myth that computers are exploding the demand for electricity was given wings by an article in Forbes, which was debunked here. In fact, as inefficient CRT monitors are being phased out in favor of newer LCD screens, computer energy use is likely to remain flat or even go down over the next several years.

and there is a lot more info so check it out

[xequence]

First answer: it depends on the processor, whether the monitor is on or off, and what the computer is doing. Are you just downloading something (linux distros, right?) or are you doing massive 3D rendering? More data is needed for a more precise answer.

Well, tonight I am encoding MP3s while having a... Uh, yep, a linux distro downloading.

But most nights it will be harmless "distro" downloading or uploading. Some rare nights it will be encoding MP3s (of cds I bought, to play on my mp3 player, yep :P) or last night it was compressing CAB files for my custom "linux" distro.

And the monitor is off. And the processor is a 700 mhz celeron, dont know how efficient it is...


Good question... I have been wondering that myself. I found this http://michaelbluejay.com/electricity/computers.html

Looks like a good read, but I am tired now, ill read it tomorow :D

[Jedeye]

the processor is a 700 mhz celeron, dont know how efficient it is...

I would think a celeron would be more efficient than a P4 Prescott

[fuscia]

if they're really concerned, tell them to eat peanut butter sandwiches and unplug the fridge.

[WildTangent]

That P3 probably doesn't consume more than 50W of power on its own. The mobo accounts for around 5W I think, hard drives 10W each, CD-ROM is about the same. All told, you're looking at less an a couple light bulbs most likely. So, if you keep some lights on at night, turn em off, problem solved :)

-Wild

[blastus]

Many appliances (including computers, speakers, printers, TVs etc...) use a small amount of power even when completely turned off. You can eliminate phantom loads by plugging in everything into a power strip and turning off the power strip when not using your computer.

[Bandit]

If you have a 17" LCD and a 2GHz CPU and less then 400w PSU. It burns about the equivalent of a 35w light bulb downloading overnight.

[ember]

I have an athlon 64 (2800+) system which uses about 80W under moderate load. In standby it takes like 5W, unfortunately only windows succeeds to put it into this suspend mode.
And even when everything is turned off here, most devices (DVD, TV, etc.) take some energy which summed up to about 20W in my case. So I decided to switch them off with an approch like blastus', because 0,020 kW * 24h * 365 * 0,20 Euro/kWh = 35 Euro / year.
So 35 Euro just disappear into the void for nothing - not very acceptable I'd say.

[majikstreet]

I have to read that site up there... my mom is upset about me leaving the computer in our basement on (used to be a server, now i just haven't turned it off), BUT she keeps her computer on all night but turns it off during the day and back on when she gets home from work..... I'd really like to leave my main computer on all the time so I can do like say SETI@Home or Folding@Home or whatever.. (i'd have to unplug my usb hub though because it has a bright light on it)...

majikstreet

[xequence]

BUT she keeps her computer on all night but turns it off during the day and back on when she gets home from work..

Thats a little odd =P

[Bandit]

Turning your computer on and off is not good for it. Everytime you turn it on it sends a power surge through the whole system. Best left turned on.
You can research each part of your computer and come up with exactly how many watts it uses per hour.
I remember gorwing up that my Dad seemed to think a computer was like some big nuclear device that sucks power from the walls like a vampire.
Little did he understand that it uses less energy in a day then his 32" Tube TV used watching the evening news.

Here take a look at the WD Raptor hard drive. http://www.westerndigital.com/en/products/Products.asp?DriveID=65&Language=en
It only uses 7.9watts on idle and 8.4watts read/wrighting.

You can go to other websites such as AMD or Intel and get the whitesheet on your CPU to get exact wattage figures also..

Cheers,
Joey

[matthinckley]

or you could buy one of these and plug your computer into it..

http://www.supermediastore.com/kilwateldet1.html

radioshack used to sell them but i guess not anymore.. couldn't find it on their website.

[erikpiper]

Kinda off topic, but what program can encode mp3's automously? I would love to know..

[xequence]

Kinda off topic, but what program can encode mp3's automously? I would love to know..

I use Multi Frontend, acting as a graphical frontend to LAME.

But it is a windows program.

[ember]

Turning your computer on and off is not good for it. Everytime you turn it on it sends a power surge through the whole system. Best left turned on.

Where did you that information from? With all due respect, I cannot really believe that this is true.

[mcduck]

Where did you that information from? With all due respect, I cannot really believe that this is true.
Well, it depends on quality of you PSU and motherboards power regulation but it is indeed true.

However, considering how fast computers become old I wouldn't worry about that. As long as there is no serious problems with your hardware it will propably last at least twice as long as you'll use it anyway..

[jnoreiko]

That P3 probably doesn't consume more than 50W of power on its own. The mobo accounts for around 5W I think, hard drives 10W each, CD-ROM is about the same. All told, you're looking at less an a couple light bulbs most likely. So, if you keep some lights on at night, turn em off, problem solved :)

Lightbulbs use about 11 - 15 W.

[ember]

Well, it depends on quality of you PSU and motherboards power regulation but it is indeed true.


O.k. I have to admit you are right. I talked to a friend with knowledge in electrical engineering and he confirmed you are right. However this problem is greatly lessened because computers use switching power supplies.

So I still state that every watt you save is a good one, at least as long as we have the world powered by regenerating energy sources.

[jnoreiko]

So I still state that every watt you save is a good one, at least as long as we have the world powered by regenerating energy sources.

Agreed.
Especially as it doesn't take much effort to switch off your PC. Ubuntu boots fast :)

[xequence]

Agreed.
Especially as it doesn't take much effort to switch off your PC. Ubuntu boots fast :)

Ubuntu boots very slow accually =P

Its not that I am too lazy to turn it off. It is I do stuff overnight like download/upload stuff, encode stuff, etc.

[zorkerz]

Quite an old thread here but you could install powertop which will give a power usage estimate only for laptops when you are on battery.

Im trying to find out how much power is used when my computer suspends and turns on because I would like to know how long i should leave my computer before it is more efficient to hibernate than to suspend.

[sailor2001]

a motor uses 300% power consumption on start-up. You can run for a long time before you get up to that consumtion.... and light bulbs vary on wattage..reading light would be 50w-200w however light you want it to be. A night light (christmas outdoor light) is 6w

[Paqman]

and light bulbs vary on wattage..reading light would be 50w-200w however light you want it to be. A night light (christmas outdoor light) is 6w

For old-fashioned incandescent bulbs that sounds about right. Energy saving bulbs are usually about 8-25W range for home use. Once we get white LEDs into the market in force that'll drop even lower.

As for leaving a PC on, unless you really need to crunch numbers for some reason, you're much better off shutting it down overnight. Power fluctuations at startup and thermal effects of heating and cooling cycles will marginally reduce reliability, but so will running constantly. The most significant factors are economic and environmental, both of which favour powering down when not in use.

[Whiffle]

I measured the consumption of my 1.6Ghz Pentium 4, Nvidia 7600 GS with 2 hard drives with a kill-a-watt and it comes out to about 90 watts at idle, 120 watts at full load, not including monitor. At 8.5 cents per kwH, that would cost me about $70 per year to run 24/7. So, I don't leave it running 24/7, I have an old laptop that pulls 15 watts of power and costs me $11 a year and I leave that on 24/7. Works great.

[The Real Dave]

Do the math :P

Wattage of PSU x Hours Used
--------------------------- x Cost per Kilowatt Hour (Unit)
1000

For example my 700 MHz P3 file server, with a 230 Watt PSU (over powered I know :P) costs about €0.80 to run for 24 hours, not taking into account the fact that units at night are cheaper. On the other hand, my main system (listed below) has a 3GHz P4, with a 500 Watt PSU, cost €1.80 to run for 24 hours.

So crack open your case and figure out what your PSU is, then do the math :)

[gn2]

Bit of an old thread but nevermind, it's still relevant.

The stated capacity of a PSU is not the amount it will draw, it is the peak amount that the manufacturers claim it can supply to the internal components.

Your 230w PSU will probably spend most of it's time drawing far less than half of 230w.
When it does supply 230w it will be drawing in the region of 290w, but only if it's a good efficient one.
It could draw much more if it's cheap and nasty.

[Polygon]

like the above poster said, the amount your PSU can support is now how much it draws, its how much it CAN draw

like i haev a 700 watt power supply, it doesn't mean i draw that all the time, i just need the power as i have 4 gigs of ram. 3 hard drives, and a beast of a video card xD

but srsly, hibernate / suspend are your friend. Its the most useful thing ever, unless you are doing something like ripping a dvd, or downloading something via HTTP, you can just hibernate/suspend and all of your programs will be working perfectly when you wake up or thaw. and it saves energy! and its faster then booting up! whats not to love?

[northwestuntu]

if they're really concerned, tell them to eat peanut butter sandwiches and unplug the fridge.

lol awesome!!! :D

then i would play beastie boys "fight for your right" really loud!!!

[The Real Dave]

Bit of an old thread but nevermind, it's still relevant.

The stated capacity of a PSU is not the amount it will draw, it is the peak amount that the manufacturers claim it can supply to the internal components.

Your 230w PSU will probably spend most of it's time drawing far less than half of 230w.
When it does supply 230w it will be drawing in the region of 290w, but only if it's a good efficient one.
It could draw much more if it's cheap and nasty.

Thanks for the info mate :D