CPU performance ac adapter vs battery

Discussion in 'MacBook' started by Nykwil, Oct 27, 2008.

  1. Nykwil macrumors 65816

    Nykwil

    Joined:
    Nov 5, 2002
    Location:
    Boston, MA
    #1
    Quick question, does the macbook underclock it's cpu when in battery mode? Or is is 2.4ghz all the time no matter what?
     
  2. Jeeves macrumors newbie

    Jeeves

    Joined:
    Oct 24, 2008
    Location:
    UK
    #2
    i know that if you take out the battery and run just on AC then it will run slower.
     
  3. logana macrumors 65816

    logana

    Joined:
    Feb 4, 2006
    Location:
    Scotland
    #3
    2.4GHz on battery
    2.4GHz on ac power with battery in place
    1.0GHz (!!) on ac power with no battery in place
     
  4. Nykwil thread starter macrumors 65816

    Nykwil

    Joined:
    Nov 5, 2002
    Location:
    Boston, MA
    #4
    weird.
     
  5. AW.kennedy macrumors member

    Joined:
    Jul 12, 2008
    Location:
    Brighton England
    #5

    ok that does make no sense to me
     
  6. misterredman macrumors 6502a

    misterredman

    Joined:
    Oct 3, 2007
    #6
    It makes sense since the mac may draw more power than the AC adapter can deliver, when doing very intensive tasks. It will then draw the power from the battery.

    If you remove the battery the mac will slow down, as a safety measure, to consume less power, since it only has the AC power.
     
  7. logana macrumors 65816

    logana

    Joined:
    Feb 4, 2006
    Location:
    Scotland
    #7
    That is the official Apple answer and I can confirm that a MacBook running on ac power with no battery runs at approx the speed of a 1GHz MacBook

    Weird but true...........
     
  8. fuzzielitlpanda macrumors 6502a

    Joined:
    Mar 24, 2008
    #8
    can you guys tell me in what normal situation would you run only on ac power (w/o the battery)?
     
  9. m1stake macrumors 68000

    Joined:
    Jan 17, 2008
    Location:
    Philly
    #9
    If you were running it for a long period of time plugged in, in order to keep the battery healthy. Stores do it with their demo models sometimes.
     
  10. logana macrumors 65816

    logana

    Joined:
    Feb 4, 2006
    Location:
    Scotland
    #10
    I have a 2.16GHz MacBook that has a water-damaged logicboard and does not recognise a battery so runs on ac power (at 1GHz). Works fine for most things but when encoding video it takes twice as long as my 2.4GHz does for the same task.....

    Some MacBook owners (who used to be PowerBook owners possibly) think that they will damage the battery if they leave it in the machine and running on ac power constantly. So they remove the battery without realizing that they are crippling the CPU speed.
     

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