Author Topic: cost of running a pc (in the UK)? (Read 34543 times)

nudone · « **on:** January 27, 2007, 03:08 AM »

i'm sure i've asked this question before (i can't find any evidence on the forum though) about the cost of running a computer. i can't remember the answer so i have to ask again.

any ideas what the typical cost of running a computer is - doesn't have to be precise, just a good idea.

if it helps i'll describe the machine: 600w psu, amd 4800, 4 hard drives, geforce 7, several fans, audigy, 24" Lcd, adsl router.

i'm sure there was a webpage that allowed you to put the details in and it worked out the cost for you but i can't find it.

(i think f0dder may have answered this last time - maybe i dreamt it all - i think i might have even said "maybe i dreamt it all" last time too. hello, hello, am still asleep?)

mouser · « **Reply #1 on:** January 27, 2007, 06:48 PM »

It's a good question, i'm sort of curious as well.
There are probably some power consumption charts on the web that you could combine with your electric company rates to get an estimate.

f0dder · « **Reply #2 on:** January 27, 2007, 08:00 PM »

I wish I knew

I found some rough power usage estimates, and for running a low-power server (using one of the low-power chips from AMD or Intel), I think it ended up at roughly £10/month here in .dk - but our power prices are probably different, and the power usage ratings might not be precise.

Should probably borrow a power rate meter thingy and check how much my own box uses.

Perry Mowbray · « **Reply #3 on:** January 27, 2007, 10:16 PM »

Should probably borrow a power rate meter thingy and check how much my own box uses.
-f0dder (January 27, 2007, 08:00 PM)

I believe that this is the only "accurate" way to measure such things; it's something that I've been meaning to do for a while...

- Perry

nudone · « **Reply #4 on:** January 28, 2007, 02:34 AM »

thanks for the replies. heaven knows where i thought i got the answer from before if no one seems to know much about it.

the power meter thing is something i once tried (borrowed one from a friend). just plug into into the electrical mains socket and the computer and read the meter - the problem was i couldn't understand the meter.

there have been several articles about computer power consumption in one of the UK pc magazines - they were talking about the environmental impact mainly - but i still can't find the webpage i've seen that allows you to input your pc details and then get a power (or wattage) score.

if i find anything i'll report back here as it sounds like it will be useful to others.

mouser · « **Reply #5 on:** January 28, 2007, 08:01 AM »

While it may be true that the only truly precise way to measure energy use is a meter, it seems to me that a simple approcimate table on thw web of the various approximate energy consumption of common pc/electronic peripherals would more than suffice.

nudone · « **Reply #6 on:** January 28, 2007, 12:11 PM »

if you search for 'cost of running a pc' in google you'll find plenty of opinion about the expense involved - quite a few erroneous calculations too, but hey, it is physics and dat makes my bwain hurt.

rather than post links to yet more forums discussing the subject i'll just state what looks appealing/satisfying to me:

it costs about £0.35, that's thirty five pence, to run a typical pc for 24 hours. it's not a precise figure and intentionally so as you'll need to plug your machine into a meter if you want a real number - just calculating by using numbers like your psu wattage won't give you an accurate result as your psu isn't likely to be used to it's full potential.

i can't say how £0.35 translates for the rest of the world as i'm sure paying for electric doesn't have a globally fixed price.

if i find a site that's worth mentioning i'll post it here but as yet i've not found anything that didn't start to make my eyes glaze over after a few paragraphs. maybe someone else will know of one.

lanux128 · « **Reply #7 on:** January 28, 2007, 09:36 PM »

i read an article somewhere in the local tech mag about the existence of online psu calculator that factors in the local electricity rates.. i will have to dig for it & will post it once i find it..

f0dder · « **Reply #8 on:** January 29, 2007, 12:29 AM »

I wonder how much PSU efficiency matters... and idle vs. fully loaded should also have quite a bit to say, depending on the PC. So I don't think there's really any way around the power meter (can it really be that hard to get such a thing to output the current wattage? O_o)

Nighted · « **Reply #9 on:** January 29, 2007, 02:20 AM »

I saw a new case with 2 PSU bays in it! Then I saw an 850 watt power supply. Actually, I think that's going to be my next case. (Lian Li is excellent quality)

Maybe in 10 years I'll buy one of those wind mills just to power my computer.

Cloq · « **Reply #10 on:** January 30, 2007, 10:46 PM »

Hmm.. not sure if they have a 220v version of this, but here in the states just plug a power strip or ups into this device (assuming all your computer equipment is plugged into the strip and/or UPS) and it will spit out watts and other information. Do the money math from there.

http://www.the-gadge...usage_monitor_review

nudone · « **Reply #11 on:** January 31, 2007, 02:32 AM »

yeah, that's the kind of thing i borrowed from a friend. but he'd lost the instructions so i had no idea what to do with it. you'd think it easy enough to figure it out but it made no sense to me.

he's currently trying to find the instructions so i can try again. i'd go out and buy one but they are about £20 in the UK and i'm not so sure i'm so committed to the cause to spend that much.

f0dder · « **Reply #12 on:** January 31, 2007, 03:45 AM »

Wow, £20 isn't too bad for such a device, really. You can borrow one from power companies in .dk, iirc at least the deposit used to be ~£50.

nudone · « **Reply #13 on:** January 31, 2007, 04:43 AM »

well, yes, £20 isn't so much. it's simply a case of i can hopefully borrow one (with instructions) which will cost me nothing or buy one.

i was going to buy before i found out that my friend had one. i suppose i'm just being tight. if he doesn't find the instructions by the end of the week i'll buy one.

f0dder · « **Reply #14 on:** January 31, 2007, 04:48 AM »

I can perfectly understand you - I probably wouldn't have enough use for one to justify spending even the measly £20 either. After all, I just want to measure my computer and a few other things (TV, gf's laptop) - and after that, I won't need a power meter for quite a while, I expect.

Then again, if you have one lying around, it might come in handy?

Carol Haynes · « **Reply #15 on:** January 31, 2007, 05:24 AM »

How can you tell?

It really depends on the electricity company you use as much as anything else as there is probably 30% variation in charges and it no longer depends on region.

Plus you have the cost of other parts of "usage" to take into account if you want to be accurate - lighting/heating where the computer is may be an essential cost for some (it is for me as the computer is in a room without windows - and it is a room I wouldn't sit in without the computer so heating is effectively part of the computer running cost), the cost of printers and standby on other peripherals, the cost of a UPS if you use one (which requires regular servicing .... note to self on this!), the cost of consumables (such as printer ink and blank disks) for essential use beacuse you 'own a computer'. Software updates and upgrades? What about devaluation and wear and tear? Specialist furniture (replacement/wear and tear on that too) ...

The list is potentially endless and varies from user to user and could all justifiably be considered as running costs on a system.

f0dder · « **Reply #16 on:** January 31, 2007, 05:54 AM »

You're not nearly thorough enough, Carol!

You have to factor in the cost of coke and pizza, small gifts to keep the significant other happy when you're hacking away for a couple of days with no time to entertain him/her, doctor bills for fixing RSI, et cetera... :]

Personally I'd just like to know what it costs to keep my box running all day, when crunching numbers or up/downloading something huge. And I'd like to know how what it'd cost to put up a fileserver again, I'd love to have my FLAC music archive available so I don't have to switch audio CDs all the time... oh, and local SVN repository + backups instead of relying on the server at my mums place.

nudone · « **Reply #17 on:** January 31, 2007, 06:01 AM »

i take your point, Carol.

but the actual meter works by the user putting in a few numbers based on what they are charged for electric - which you'd get from your electric company. hopefully somewhere off the bill.

lanux128 · « **Reply #18 on:** February 04, 2007, 08:36 PM »

this is what i managed to find out:
How do I find out how much electricity something uses?
- http://michaelblueja...tricity/howmuch.html

Calculate the Potential Savings from Power Managing Your Computers
http://pmdb.cadmusde...ement/quickCalc.html

not an exact science, but close..

Notok · « **Reply #19 on:** February 08, 2007, 08:42 PM »

You could always get one of these

http://www.thinkgeek...ets/electronic/7657/

Efficiency does make a big difference. Higher wattage PSU's running at low wattage levels are also more efficient than low wattage PSU's running closer to capacity. PSU's that aren't efficient waste power, releasing the wasted energy in the form of heat - which also causes more errors that need to be made up for, making the computer do more (which is why better cooling can sometimes make a system run a bit smoother.. the difference was noticeable the first time I used RAM heat spreaders).

nudone · « **Reply #20 on:** February 22, 2007, 10:46 AM »

right. i've finally managed to get hold of one of those meter things.

it's a "PM-230 electricity meter" like this http://www.taperecorder.co.uk/energy.htm

i've also calculated the cost of running a few devices. this is what i did if you wish to follow along...

used UKPower Cost Calculator http://www.ukpower.c...nning-costs-elec.asp

checked that 10 pence seemed like a reasonable cost for kWh by looking at a pdf file i can't find the link for now - it was for prices starting march 2007 so it looked okay to me.

i used the pm-230 meter gadget to give me the wattage readings for the devices i plugged into it. i didn't bother messing around putting the costs of electric into the device as it was too much for me to read the instructions.

after taking the wattage reading i put that directly into the UKPower cost calculator where it says "(Start from here if Wattage known)" and then i put the hours of use in to the month field. BUT i've ignored the monthly method and just calculated for 24 hours constant use a day, i.e. i put 24 into 'average hours used a month' field and accepted the final result as representing a single day - not a month. (i appreciate you could do a lot of this in your head as the calculations use multiples of 10 but i don't trust my mental arithmetic.)

here are my results:

all costs are for running devices for 24 hours at 10 pence per kWh

main pc setup = £0.54 (i.e. 54 pence to run for 24 hours)
adsl wifi router
24" LCD monitor
amd 4800 dual core cpu, 4 hard drives, geforce 7800, audigy x-fi, 600w psu, several fans
creative 5.1 speakers

without the monitor on at all = £0.40

interestingly, if the monitor and speakers were OFF but remained connected to the mains electric supply they consumed about 4 watts (this wastage gets even worse for other devices as you will see below).

old pc = £0.52
amd athlon 2200, 1 hard drive, non 3d graphics, standard sound card
19" CRT monitor

without monitor on at all = £0.29

and, oh dear, with both pc and monitor OFF but still plugged in at the wall they consumed 46 watts, i.e. £0.11 a day just for doing absolutely nothing at all!!! (the pc used 31 watts when 'OFF' and the monitor 14 watts when off. that's without any LEDs flashing or any indication of the devices being on at all.)

pentium 4 laptop = £0.17
with wifi and 128meg 3d graphics

pentium 2 laptop = £0.06
with wifi card

old apple ibook g4 = £0.08
plugged in but turned off = £0.02

here are a couple of other things

32" widescreen CRT TV = £0.31
on standby = £0.02

14" portable CRT TV = £0.12

i hope that gives you some idea of the price. you can, of course, divide my results by 24 to get the hourly cost.

i think the most interesting thing is the power consumed by devices that are 'OFF'. i know we've been told in the UK to not leave things on standby but i was surprised to see just how bad my old pc and CRT monitor are at wasting energy when they are meant to be off - this is not even standby.

also i think it interesting that my newer pc with 4 hard drives, big 3d card and stuff consumes little more energy than my old amd 2200 machine with hardly anything in it. i know my 600watt psu is meant to be very good at not wasting energy (i.e. heat waste or whatever you want to define it as) but i'm still surprised by the comparison. i guess if i started heavy cpu tasks the power consumption would go up - i should have tested it.

iphigenie · « **Reply #21 on:** February 22, 2007, 11:28 AM »

Well it might mean that when you turn your pc or monitor off something is not really turned off and still using some power...

Were they plugged in directly in the measuring tool or maybe in a fancy surge protecting rail?

I have been looking at http://www.electrisave.co.uk/ - a bit more expensive but you can go around your house and measure what changes when you turn things on/off. Can be found for between £60 and £79 different places around the net. This is making me actually jump and order it

nudone · « **Reply #22 on:** February 22, 2007, 12:19 PM »

exactly, it does mean that the older pc and monitor aren't really off when they appear to be. they are obviously consuming power even though they have been 'turned off' on their front panel on/off switches. during the test they were plugged directly into the meter which then plugged into the mains electric socket. so, it's quite clear that some electrical products simply use power when they have no good reason to. i know some motherboards are set to boot from LAN so they would require power but why on earth does a monitor need to consume electric when it's meant to be completely OFF.

yes, a little trickle of power, i understand that. i tested other devices that were clearly in standby mode and yet they had almost zero power consumption - but this was enough to keep a time display going on their front panel. so there is absolutely no good reason for many products to consume energy in standby mode like the ones i found.

i appreciate that most equipment these days is never really OFF as today's on/off buttons aren't even like the ones we had 20 years ago.

iphigenie, that other device you mentioned for 60-80 quid looks a bit expensive. it's not really going to tell you anything more than the ones that cost around £20. so, you could save yourself nearly 60 quid and then just do the calculations yourself by finding a bit of info online. the wattage is the important thing and you can even get that from the label on the thing you are testing - i just wanted to know for sure what a pc would use as the consumption isn't going to be exactly what the psu states (not that such things really matter when you are talking about days or weeks or months average use).

Ruffnekk · « **Reply #23 on:** February 22, 2007, 12:53 PM »

I heard about devices consuming power while 'off' before, but I never reckoned they would consume so much! Since the device is not really 'using' power, I wonder if it's the result of some sort of leakage.

nudone · « **Reply #24 on:** February 22, 2007, 01:04 PM »

well they are old machines. can't remember exactly but the monitor must be 10 years old. maybe that explains it??? it was a high quality monitor at the time i bought it.

i've just remembered something about the older pc - i think i've got a midi keyboard plugged into it - that could possibly be drawing power. i know it did something weird regarding power but i can't remember what it is now. but that wouldn't excuse the monitor doing what it does.