kernel_task uses 10-15% CPU constantly

Discussion in 'Mac Basics and Help' started by v1nsai, Jan 29, 2014.

  1. v1nsai macrumors newbie

    Joined:
    Jul 21, 2012
    #1
    Recently I noticed that kernel_task is constantly using CPU. I've looked around and seen lots of threads where people are complaining that kernel_task is running wild and using 100% CPU and over a gig of RAM, but mine is steadily using about 350 MB of RAM which seems normal, but is constantly using at least 10% CPU, sometimes as much as 20 when my system is just idling. Is this normal? I'm on Mavericks and I'm really starting to distrust it, so maybe I'm just being paranoid.

    Thanks for any insight.
     
  2. simon48 macrumors 65816

    simon48

    Joined:
    Sep 1, 2010
    #2
    How long has it been going this? Does it still run like this if you restart?
     
  3. Weaselboy Moderator

    Weaselboy

    Staff Member

    Joined:
    Jan 23, 2005
    Location:
    California
    #3
    That is not normal. 1-2% when idling (or less) is more like it.

    Thing is, this is not likely anything wrong with kernel task. Think of kernel task as the traffic police for system operations. Many of the processes used to run the machine are managed by kernel task, so if some other process is running amok it will often show up as high kernel task usage. So high KT usage is a symptom and not really the problem ordinarily.

    When this is happening look in that same CPU tab of Activity Monitor and sort by CPU% and look for other things that are chewing up CPU cycles. Those are more likely what is causing KT to show high cpu usage and where you should focus your efforts.

    Also, try a checking CPU usage after a safe mode boot by holding shift key when you boot. This will bypass any login/startup items you have setup and eliminate that as the culprit.
     
  4. northernmunky macrumors 6502a

    northernmunky

    Joined:
    Jan 19, 2007
    Location:
    London, Taipei
    #4
    Hi
    Quick post. I had this issue with my old non retina Core i7 Macbook Pro. It took forever but I eventually figured out it was caused whenever multitasking with high intensity apps or when rendering for example and the CPU gets hot... its some sort of method it uses to eat up CPU cycles to stop the CPU from overheating.

    My solution was to get myself a fan for under the laptop and the problem went away. You can also use gfxCardStatus to manually force the on board Intel graphics chip to stay in use as the discrete one tends to get a lot hotter.
     
  5. v1nsai thread starter macrumors newbie

    Joined:
    Jul 21, 2012
    #5
    I started having problems with Mail.app and turned my attention to that, a simple restart appears to have solved both. I'm not happy with that solution but as long as it doesn't happen again I suppose I can live with it.....
     

Share This Page