How much does it cost to leave a PC on overnight?

Discussion in 'Power Supplies' started by dmagro, Mar 17, 2009.

  1. dmagro

    dmagro Limp Gawd

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    I really haven't thought much about this, and habitually always leave my PC on, 24 hours a day.

    Has anyone figured out more or less how much it actually costs, for a basic, and more advanced PCs?

    Mine is pretty simple, has a 650w PSU, a Q6600@ 3.0Ghz, a simple HDD and a HD4850 with a 24" monitor. The monitor goes to sleep after an hour or so, the PC does some minor energy saving mode (I can't stand the full sleep mode - at least on my previous PC).

    Even rough estimates, anyone have any idea how much it actually costs to keep it on all the time? And how much of a difference is it from something fairly simple like mine, to a monstrosity of a PC?
     
  2. StorageJoe

    StorageJoe Limp Gawd

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  3. BillParrish

    BillParrish [H]ardness Supreme

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    Look at the back of your power bill or go to their web site and get the residential rate. I am paying about 10 cents per kilowatt hour or $.1/KWh.

    Find out how much your PC actually draws from the wall with the device mentioned above or just estimate 200w for an idle or low load PC ( 200w is just a wild ass guess)

    Define a "night' say 10 hours. again use a number that fits your situation.

    200W x 10 hours = 2000Watt-hours = 2kWh

    2kWh x $.1 per kWh = $.2 (twently cents) for 10 hours.

    say for ease of math each month has 30 days so:

    $.2 x 30 = $6.00 for 200W per 10 hour night over 30 days.

    $6.00 x 12 months = $72 year.



    Note my rates are fairly cheap. Some places its 20 cents or more which would double the cost.

    If you took the $6 bucks each month and could get 4% interest compounded monthly at the end of 20 years you would have:

    Total Amount Invested $ 1446.00
    Interest Earned $ 775.32
    Final Balance $ 2221.32
     
  4. ryan_975

    ryan_975 [H]ardForum Junkie

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    lol, I love my $0.035 / kWh winter rate.


    There's no way to make a list of exact or even average cost for a given PC because everyone's power rates are different depending on the area they live in and the time of the year it is.
     
  5. iTYPE

    iTYPE Limp Gawd

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    I think he was shoot'n more for the thought than the actual ammount.

     
  6. BillParrish

    BillParrish [H]ardness Supreme

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    The rate schedules give exact details of what the cost is when, it just turns the math from a 5th grade problem to a 8th grade problem. The actual power draw is the really hard thing to determine but a product like was mentioned in post 2 is fairly accurate.

    The real point is to get an idea, even if rough, of what it costs. It is enlightening to figure out what a 100W light bulb costs for 8 hours a day. Also of interest at least to me is, given a life of 2000 hours figure the cost over the life of that bulb (not forgetting the initial cost of the bulb) and then compare it to the cost over the life of one of those compact fluorescent bulbs. You will quickly appreciate why your Ole man was constantly yelling at you to turn off unused lights and not stand in front of the open fridge. Individually its just peanuts, start adding up the peanuts and it can become a decent pile of peanuts.

    I am not a tree hugger by any means but is it my opinion it pretty silly to toss money away. Of course if we all saved energy like mad the utililty would lose revenue and petition for a rate increase and we would end up paying the same for less energy anyway. I love America.


    I provided the example so that anyone with any interest in such a question could easily plug in their unique numbers to fit their situation. At least one would hope they could.
     
  7. ryan_975

    ryan_975 [H]ardForum Junkie

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    The yellow says otherwise. He's wanting numbers, even if somewhat vague. The problem is, my numbers (based on my $0.035 rate) would be way off if he's paying $0.12/kWh.
     
  8. dmagro

    dmagro Limp Gawd

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    The 3rd post was very helpful, thanks! (2nd reply)

    I suppose I'm very surprised at the disparity of electric cost, but would still be curious to see numbers from others who have figured out their estimated cost for ~10 hours of idle time.
     
  9. Raiden911

    Raiden911 Gawd

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    I am going to get that when the deal pops out. That would help a lot in combination with the 3rd post calculation to an extent with different cents price per kilowatt hour.
     
  10. SpeedEuphoria

    SpeedEuphoria Limp Gawd

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    My guess is ~150w at idle with the above setup, but depends on if you have Speedstep enabled and or how low your 4850 clocks at idle. It also depends much on the mobo if its power hungry or not.

    I idle at ~120w Q9650(2.4Ghz@.1v) my E8400 idled at 10w less on same settings, 4850(low as I can get), 3x HDD's and 3x 120mm fans running low). With the 4850 left alone its 135w idle add cpu at 3.6 its 145w idle. With an Antec TP3 550w psu.
     
  11. Nenu

    Nenu [H]ardened

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    Yeah I reckon about that.
    So 8hrs overnight will use up a bit more than 1KWh if the monitor and other devices are turned off.
    In the UK thats 10p +.
     
  12. rewted

    rewted [H]ard|Gawd

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    The last I figured my system costs approx $20 per month to run 24/7 like it does....it pulls around 230 watts @ idle.

    Under load it pulls close to 800 watts...just imagine if i was doing something cuda 24/7 like folding or something to that effect. ZBoned for the electric bill, heh.
     
  13. Monkey God

    Monkey God Mangina Full of Sand

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    My PC uses @ 125W at idle. (Via APC UPS tool)
    8 hours * 125 * = 1kw * .09$ = ~$1?

    (checkzor my maths plz)
     
  14. Nenu

    Nenu [H]ardened

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    heh, 1KWh = $0.09 so it costs $0.09
     
  15. Monkey God

    Monkey God Mangina Full of Sand

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    9 cents? thats trivial. neat.
     
  16. Nenu

    Nenu [H]ardened

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    Check the prices where you live and for your supplier.
    It shouldnt be much different.
     
  17. ryan_975

    ryan_975 [H]ardForum Junkie

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    9 cents per day. $2.70 per month.

    I'll add mine for the hell of it.

    Assuming I'm using all of my 650 watt's capability. At 80% efficiency, that's 812.5 watts or .8125 kW from the wall.

    .812 * $0.035 = $0.0284 * 10 hrs = $0.284 * 30 days = $8.53
     
  18. spacetrader

    spacetrader 2[H]4U

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    normal modern pc's with normal electric rates go between $10-$20 a month per pc to run 24/7. that's why its so important to use sleep functions and turn off monitors and such. with window's power saving features enabled to turn on at set timeouts, i find you can easily knock off 30% or more savings. but if you use low power cpu's, green drives and all the other power saving stuff, you can easily keep a pc running all month for a couple bucks. this is why i paid $30 to change out my server pc with a dedicated video card to one thats integrated... itll pay for itself in a year most likely.
     
  19. JonDoms

    JonDoms Gawd

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    I agree with your suggestions and think that changing out the server video card is going to be a great idea for me.

    I wonder how much power difference there is between S1 -> S3 -> and S4 sleep.
     
  20. ryan_975

    ryan_975 [H]ardForum Junkie

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    Well, S1 and S3 really depend on how well you system's components lower their power usage. And there's no difference between S4 and power off as far as power usage goes.
     
  21. CraftyChicken

    CraftyChicken Limp Gawd

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    My system draws around 250 watts while running F@H.

    At a night rate of about $0.08 per kWh, very cheap compared to the national average , I figure it costs me about $7 a month to keep my machine up all night, 12 hours. (12 hours * 0.175 kWh * $0.08 * 30 days).

    If you are looking at it from an enviornmental perspective, if running your machine at night increases productivity it's a good thing, as peak demand is at it's lowest at night. From a budget perspective, it's probably not such a good thing. That's $80 a year, or almost the price of 2 video games for me. For some reason, Uncle Sam doesn't think this is worthy of a tax deduction, otherwise I'd have all the machines at work running F@H 24/7.

    -My 2 1/2 cents
     
  22. rewted

    rewted [H]ard|Gawd

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    Yeah and I have a spare i7 box that is going to be folding mostly....i want a tax write off! :)
     
  23. spacetrader

    spacetrader 2[H]4U

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    im curious too, as to what real-world measurements are, but i know 'they' always say to unplug your stuff because even sleep modes draw a lot of power. well, if you ask me, unplugging stuff is not an everyday option, and sleep modes DO save tons of power... so if 'they' want machines to use less power in sleep modes then 'they' need to make that happen.
     
  24. gwarren007

    gwarren007 [H]ardForum Junkie

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    Running everything onboard, 1 -320gb hard drive, a q6600 stock, 1dvd burner and running folding at home @90% load runs 12.00 a month here in tucson.
     
  25. SpeedEuphoria

    SpeedEuphoria Limp Gawd

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    My new setup pulls 2w when off and the same with S3. With the same psu on my old DFI board it drew 6-7w when off. I have 2 other computers that are older and they both draw 6-7w when off.

    Its still better than my older 27" TV that draws 10w when off, or my craptastic Comcast cable box that draws 17w when off(only 18w when on WTF?)
     
  26. Omegas

    Omegas [H]ardForum Junkie

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    If it's a DVR then it's never off unless you unplug it. Can't record those timed shows if it was really off eh? =)
     
  27. Nenu

    Nenu [H]ardened

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    My Humax Foxsat powers down properly, only using a few watts idle.