Why I've re-enabled the SleepImage on my '13 MBA

Discussion in 'MacBook Air' started by RightMACatU, Oct 6, 2013.

  1. RightMACatU macrumors 65816


    Jul 12, 2012
    I've always thought that my 8GB SleepImage was useless since I will never be in a situation where I would loose power in Sleep mode, so I disabled it on my '13 MBA (13"/i7/8/512).

    But after a few days I re-enabled it for power reasons. Without a SleepImage, the MBA keeps the RAM 'alive' in Sleep mode pass the default 4200 seconds (70 minutes) since it can't write the contents of RAM to it and won't go into a deep sleep to save power.

    The results of no SleepImage were quite impressive: my 12-hour capable battery lost about 25% of juice per period of 8 hours in overnight Sleep mode :eek:

    Since I've restored the SleepImage, an 8 hours Sleep period will cost in the ball park of 2 to 4% :cool:
  2. Mrbobb macrumors 601

    Aug 27, 2012
    Makes sense the way you said it, now I assume you also reconfigured sleep mode, not just deleted the file right.

    My NO sleep image machine takes 8% juice in 8 hours, but I do have powerNAP disabled on battery.

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