UMB much cooler when running on battery?

Discussion in 'MacBook' started by handydandy, Jun 16, 2009.

  1. handydandy macrumors newbie

    May 16, 2009
    when im doing intensive work with the charger plugged in (at 100% charge) the cpu temp goes up to 70, but when im in battery mode with it unplugged, it is only about 58 c.

    why is it so much cooler when running on battery? does it decrease performance when on battery to improve battery?
  2. indiankid macrumors newbie

    Jun 16, 2009
    Isn't that supposed to be really bad for your battery, to plug it in while it is at 100%?
    My sister did that with her laptop and eventually her battery died out to the point where the battery would die in 5 minutes.
  3. davwin macrumors regular

    Nov 4, 2008
    I believe the uMB's have default power profiles for On and Off charger. So when on the charger, your uMB would be running at full speed and draw full power and would thereby be generating more heat. While on battery only it would default to a slower, "power save" profile (for lack of a better expression) with a lower clock rate, etc which would draw less power and generate less heat.

    If I recall correctly you can change these profiles in the System menu so that it does not default to "power save" when on battery only but, this will of course drain your battery much more quickly and generate more heat...

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