Power consumption

[neo75903]

Hi,

I have been thinking how much our pcs use in terms of power? How does it compare to other home appliances like fridges, tv, cooking plates, ...?
I think this will become increasing importantas we are starting to think leave a pc on for 24/24.
Hereby i declare debat started :)

[mpucoder]

I think of it this way - since I have electric heat it doesn't matter in the winter. I also jokingly call my Athlons "space heaters". They have 400 to 500 watt power supplies for a reason.

[neo75903]

hmm lets make an example.
400W*24(hours)*7(days)*52(weeks)=3494400W/year
Lets say 7c€/kWh, (3494400/1000)*15c€/kWh=524.16€/year.
approx. 524€ each year sounds a lot of money. costs are even higher if you have multiple pcs in the house like we do.

Makes you think about more energy savings measures :)

PS: 15c€ includes actual electricity cost and distribution costs. Which are now seperated due to freeing up the market in EU. And therefor may be a bit deifferent.

[Atamido]

That would be operating at full load. When a computer is idle (much of the time) it will draw far less than that. Still, having a PC that uses $100 in electricity each year is probably not uncommon. Plus, if you use air conditioning, you figure in the cost to cool your living area back down.

Also, where I am at it works on a scale. So the more you use, the more you pay.

First 500KWH is $0.0355/KWH
Then it moves up to $0.0782/KWH
I'm not sure anymore where the next break is at.
Then there is the fuel charge which is $0.02796/KWH.

Last month I used 1235KWH, so after taxes and fees, the total was $116.92USD. That's about 89.36EUR.

Even at 400W*24*30/1000=288KWH usage for my PC last month, plus the cooling.

[Mug Funky]

add more to that if you are in the habit of using the computer with the light on :rolleyes:

plus anything external will use power - including chargers that you've left plugged in. though not much, transformers use power when idle.

[neo75903]

Originally posted by Pamel
That would be operating at full load. When a computer is idle (much of the time) it will draw far less than that. Still, having a PC that uses $100 in electricity each year is probably not uncommon.

My pcs are running Seti when they are idle :)

approx. 90€/month* 12 months = 1080€/year! and your pc uses about 23 percent of the total. 1080*0.23=248.4 approx the same amount i pay as well. Thought things were cheaper in the US.

I think someone should do a report on "energy use by modern IT". Think I will have Greenpeace on my doorstep in no time.

@mug Funky:
Idd, we used to use energy to survive like cooking. Now we use more energy to keep our luxury life style. I think i am going to join the Amish community :)

[Atamido]

Originally posted by Mug Funky
add more to that if you are in the habit of using the computer with the light on :rolleyes:

plus anything external will use power - including chargers that you've left plugged in. though not much, transformers use power when idle. I typically don't use a light when using my PC as it is near a window. And when I do, it is a flourescent light that uses only 30W I think. Of my peripherals, my printer and mouser receiver both have power adapters, but the printer is off unless I need it and the reciever can't possibly use that much.

Of course, I wonder how much power my 21" CRT uses. ;)

[slavickas]

Originally posted by neo75903
hmm lets make an example.
400W*...
maybe fastest prescott with 6800 ultra + lot of hdd could use 400W, but typical athlon system should be <200W (excluding monitor :))

[Mug Funky]

how bout this:

my headphones are being fixed (hopefully) at the moment, so i've taken to running a lead out to my hifi amp. plus, to clean up the cable noise i need the TV on (please don't ask me why this works... it just does, but i haven't hit on a good reason why yet).

total consumption there is about 480 watts, and i tend to leave it on all the time.

good thing it's not a class A amp... then i'd be burning heaps of power (i should be so lucky as to have a 65 watt class A!). those things are at absolute max power when there's zero output...

[edit - byob]

[zilog jones]

I think the hi-fi my PC's connected to uses more power than the PC itself! I only have a crappy Pentium III, which dissipates about 30W compared to a 3GHz P4 which is about 100W (similar Athlons are a bit lower) - and that's just the processor on its own!

The hi-fi's an early 90's Pioneer which generates about 150W. OK, that's probably about the same as my PC.

What kind of speakers you use can make a BIG difference! My crappy old Altec PC speakers were only about 25W. Also, compare our old 15" CRT (75W) compared to a 15" LCD (about 25W) - if you're using a big CRT, like a 19", that can be 150W or more! There's much more than just the PC to think about.

And don't forget about the power-saving features your PC has! Having it so your monitor goes on standby (or even just turning it off when you're not personally using the PC) can save you a lot, as will letting other components go off when not being used*, and unplugging stuff like your printer and scanner when you don't need them. You *really* should think about this kind of stuff if you're planning on leaving your PC on permanently - it can make a big difference!

*There has been many debates as to whether using the power management features for your hard disk is worth it, as the actual switching on and off of a HDD is were most wear/stress is put on it. However, I doubt turning one on and off once is going to wear it as much as leaving it spin for 8-12 hours when the PC's not doing anything, so it's questionable.

[neo75903]

@slavickas:
not really, had a 350power supply who blew up due to overload. I got a 400 which still runs very hot. Should have opt for a 500watt one but then i believed the sales man. :/
Two Athlons MPs can draw a lot of power!

and as Mug funcky points out, we dont always have 'only' a pc on, also an amp, second mon, active woofer, another tv, ....


@zilog jones:
Have your pc do something useful if you have it switched on all the time. Well useful things like virus scanning, defrag, ..., seti ;), but then the hd will be used anyway and power saving have no way to kick in at all.

[unmei]

wow some of you guys seem to have PCs that eat more than mine two combined..
I have this P3/600 running 24/7 but it has the CRT turned off until i'm actually at the keyboard, it has a couple of harddrives, but apart from that i think it uses "few" Watts, it has a 230W PSU and i guess in idle state it bare consumes more than 100W. Then i have an Athlon, that one uses a bit more also because of the GFX, but then again it's TFT use 4W idle and <40W in operation. My old scanner used to eat a lot of power, but the new one is USB-fed so i think it can't be too much (besides its finally turned off when the comp doesn't run).

I can't give you exact numbers though, only thing i know is i paid 36CHF/month (~30+$/25E or so) for electricity and water combined averaged over the last year. This is only 75% of what they expected (i had to pre-pay), so i think my comps can't hurt too much compared to ther peoples TVs, always-running hifis, hi-watts lights (my main lamps use 66 watts compbined) etc. ..oh well i also don't have a garden to water or a pool :)

[zilog jones]

@zilog jones:
Have your pc do something useful if you have it switched on all the time. Well useful things like virus scanning, defrag, ..., seti ;), but then the hd will be used anyway and power saving have no way to kick in at all. [/B]

I don't leave my PC on all the time - I was just saying. I'd sometimes leave it on overnight when I'm encoding stuff - with my crappy P3 it takes a good few hours to encode a film to XviD!!:D

Defragging takes about 5 minutes max. for me these days - I do it quite regularly, and always after installing/uninstalling stuff. The 5 partitions for my 80 gig hdd might be helping that ^_^

[PiXuS]

Like Pamel already pointed out, your PC never use 400W. You buy a power supply that has enough "room" so that no components of your computer will ever fail to draw the energy it needs.

Even if you run Seti all day long, it will never drain the 400W of your PS!! You need a 400W PS if you have many HDD and/or CD/DVD-ROMs... stuff that draw a lot of current on startup... some video card demand more power too.

Anyway.. the point is that a 400W power supply simply has more power AVAILABLE IF NEEDED.


zilog jones mentionned his amp draws 150W. That too is not continuous... that's the MAX power that can be drawn from the unit.

[neo75903]

that is for most of the cases. But i will be pretty close to my 400w usage.
-6hds
-RAID controller
-6 Vantex HD holder, each with LCD display and own fans.
-7 cooling fans from 1*80, 1*90, 2*120
-Capture card.
-...

I think that pretty much it.

[markrb]

It's not really for the "room" as much as for the peak. Just like Hi-fi systems that put out 200W's, but only for a half second. Computers have peaks as well. When motors first start as in your DVD drive they draw much more power to start spinning then to keep the spinning going. The same is true for other parts of the PC as well. You may very well get away with using a low power PSU, but at certain times the voltage will drop to keep the amps up and that can cause system instability.
Also a tremendous amount of power is lost to heat when the systems are being pushed. The PSU has to make up for the loss. A cooler system runs far more effciently, but in PC's today it's really easier and more pratical to throw more power at it then cool it.

Mark

[dani82]

how much watts does 4 different types of cd-rom consum when not in use?

since i only use them maybe twice a week, is it better to just unplug them until then?

[neo75903]

@markrb:
true, but my CD rom is idle most of the time, dont use them a lot.
Dont think it will matter wheter to unplug my CD unit.
My PSU is 400W whihc can handle peaks up to 500W.
I think i am going to buy one of those watt usage meter to have a exact clue how much my pc uses.

Is it true you can plugin a Athlon mobile into a normal motherboard?

[Tuesday]

There's quite a few power usage calculators out there, personally i use this when designing systems:

http://www.jscustompcs.com/power_supply/

Dunno exatly how accurate it is though

[neo75903]

approx. 357W for my workstation.
approx. 391W for my server.