7 Replies Latest reply: Mar 7, 2013 10:26 PM by FrenchToast
(n_n) Level 2 (345 points)

Greetings,

 

Once I turned on my wifi, kernel_task will immediately takes up 25~30% CPU usage and causing my fan to kick in. Without having wifi turning on, kernel_task will only take up 1% CPU usage. How can I resolve it?

 

Thanks!!

 

Cheers.


 MacBookAir1,1 (The GrandPAir), Mac OS X (10.6.8), ✓1.6GHz ✓80GB SATA Drive ✓SuperDrive ♬Monster Turbine
  • (n_n) Level 2 (345 points)

    Hi all,

     

    I tried to connect wifi to other hotspot and it remains taking up 1% of CPU usage so i think it's *that* particular hotspot causing the problem.

     

    Thanks.

     

    Cheers.

  • FrenchToast Level 3 (645 points)

    25 to 30% isn't so bad. Activating WiFi will start a bunch of kernel extensions, hence the increase in activity on the kernel front. It should actually peak every once in a while to 30%, then go back down to 10% or so. If you suspect there's something wrong with your WiFi, uninstall the connection, then recreate it in System Preferences.  Using your Mac in a hotspot where reception is poor is bound to cause your Airport chip to work overtime to maintain the connection, anyway.

  • (n_n) Level 2 (345 points)

    Hi,

     

    Just curious. Can it be the flashback trojan that affecting the kernel_task? Thanks!

     

    http://www.bbc.co.uk/news/science-environment-17623422

     

    Cheers.

  • FrenchToast Level 3 (645 points)

    Don't see why, but if you think you might have been infected, go there and enter the commands presented by (the excellent) Linc Davis. The guy knows what he's talking about...

  • (n_n) Level 2 (345 points)

    Hi,

     

    I've tried the suggestions and nothing turns out so I'm safe I guess.

     

    Merci beaucoup.

     

    Cheers.

  • marknak8 Level 1 (0 points)

    I have the same problem. When wifi turns off or i re-connect to any network, kernel_task goes %100 ~ %105 and starts to cook the cpu hence loud cooling fan and poor battery life.

     

    Only happens in case of connecting to wifi, or reconnecting to any other wifi (or even the same)

    Once it happens, kernel_task never settles down until full shutdown. really annoying.

    Can someone help please?

     

    Macbook air (4,2) on 10.8.2

  • FrenchToast Level 3 (645 points)

    I've had this same problem since... 2006, and the very first day I started using my 1.83GHz MacBook Pro. Only solutions I've found (after years of hard shutdowns caused by CPU overheating) was to:

     

    - Install an app. called Coolbook Switcher, though it's not going to help in your case, since it doesn't support your CPU;

     

    - Install ATMonitor (freeware), set it to start at logon, and renice (don't forget to click "Renice and remember") all CPU consuming processes to, say, a minus twenty value. It won't slow your MBA down by much, and prevent overheating. Works like a charm for me.

     

    My two cents!