The activity monitor for Mavericks running on my 2013 MacBook Pro Retina lists a column "Idle Wake Ups" that is new to me, and Google and Apple Support Forum searches were unrevealing as to what it is telling me. I would welcome any advice about this measure and how I can use it to assess the activity of various processes.

  • Just guessing, maybe it's counting how many times it has woken up after it went to sleep because it was idling for some time? What values do you get?
    – gronostaj
    Nov 18, 2013 at 22:32
  • Thank you for your interest in my question. The numbers range from the single digits to 1200+.
    – user8624
    Nov 20, 2013 at 18:09

2 Answers 2


Mavericks performs some advanced timer coalescing to reduce power consumption. Apple claims up to a 72% reduction in CPU activity. I think (but am still searching for written proof) that Idle Wake Ups is the number of times the CPU leaves the idle-state per quanta of time. I'm not sure what that quanta is (probably one second).

You can read more about Maverick's power savings at Ars Technica's excellent review of OSX 10.9 (page 12, "Energy Savings").

  • You mention Mavericks specifically: Is this to say that Yosemite and beyond are less optimal in power saving than Mavericks? Sep 13, 2016 at 18:20
  • At the time he commented Mavericks was the latest. Later versions also had it and probably improved on it even.
    – Pixy
    Feb 28, 2017 at 22:40
  • I really wish Activity Monitor would specify the quanta of time, e.g. "Idle Wake Ups/sec" or similar. I wonder if the quanta is based on the update frequency.
    – jvriesem
    Jan 1, 2021 at 16:14

According to Intel an Idle Wake Up is the

Number of times a thread caused the system to wake up from idleness to begin executing the thread.

Source: Idle Wake-ups (Intel.com)

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