24" iMac power consumption

Discussion in 'iMac' started by zimagold, Feb 16, 2009.

  1. zimagold macrumors newbie

    Sep 30, 2007
    Got myself an energy meter over the weekend and have been plugging things in to measure power consumption. The iMac was interesting because in sleep mode, it consumes 3 watts, but when it's powered off, it also consumes 3 watts. This is good since I never power off the iMac completely.

    I have the 24" Aluminum 2.4Ghz. At idle it's around 95 watts, and while playing back a 1080p x.264 video, it's about 115 watts.

    Other stuff of note:
    - Almost every AC adapter wall wart draws about 2-3 watts just plugged in
    - Xbox 360 draws 7 watts when it's off
    - My 12" Powerbook G4 only draws 15 watts with screen at half brightness. Wow!
  2. rfrankl macrumors 6502a

    Apr 15, 2006
  3. JBWade macrumors newbie

    Feb 5, 2009
    How much power does your Powerbook pull when you take out the battery and run on straight A/C power? I wonder if the battery could be acting as some sort of "load leveler"...
  4. Digitalflick macrumors regular

    Aug 19, 2002
    Interesting, so how much is it a day to leave your imac on?
  5. zimagold thread starter macrumors newbie

    Sep 30, 2007
    No difference with the battery pulled out. Hovers around 15-20 watts doing normal stuff. With the CPU at 100% and screen brightness all the way up, it's still under 40 watts.

    One of the problems I have with the iMac is that sometimes it doesn't go to sleep. The display will sleep, but some program or process is preventing the system from entering sleep. And with no visual indicator that the computer is on at all, I will unintentionally leave it on all day just idling. With the 24" display sleeping but computer idling, it's 50 watts (compared to 95 watts idling with screen on).

    I pay about 6 cents/kWh, so that's about 16 cents per day to run the iMac with screen on all the time. If I put the computer to sleep 8 hrs/day, that'll make it about a dime a day....not bad at all.
  6. johnsy macrumors 6502

    Nov 15, 2006
    If you worry about electricity and money :) download utility Caffeine and adjust power settings. I have my display off after 1 minute inactivity, computer sleep after 15 minutes and hd sleep when possible. When I make myself a cup of tea for example display goes to sleep, when I use my computer I turn on Caffeine.

    Beware that computer and HD sleep should be adjusted if you downloading big files and want download to finish. In this case only screen should sleep.

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