kernel_task - taking up over 200% CPU usage??

olletsocmit

macrumors 6502
Original poster
Jun 24, 2010
296
2
USA
My MBP has been running super slow the last 2-3 days. It is very very lagy! When i just opened activity monitor, I noticed that Kernel_task was running at over 200% CPU usage, it is also running super hot. I am not able to stop this process either, what the heck is going on???

see below:
 

Samuelsan2001

macrumors 604
Oct 24, 2013
7,694
2,121
Really? thats a real pain in the ass. It came out of no where. there has to be something that changed. dont see how it just happeded out of no where like this.
Well you could do an SMC and PRAM reset and repair disk first and see how that goes....

They will often clear an issue this, although it's annoying that you don't know what the issue is afterwards.
 

olletsocmit

macrumors 6502
Original poster
Jun 24, 2010
296
2
USA
I just noticed that firefox was just also running at over 100% cpu usage and some other things are close as well. is this normal?
 

joe-h2o

macrumors 6502a
Jun 24, 2012
997
445
Kernel task is the kernel of the OS - it's the main "brain" of the OS so you can't quit it or you'll crash the computer. Everything else in the system depends on it, so if it does crash it's what's called a kernel panic and is why when it happens it's not graceful - the system simply stops and says "restart your computer".

Very high CPU usage of that task suggests that one of the drivers in the kernel is playing up. The first thing to do after trying a simple reboot is to try and reset the PRAM and SMC (check Apple's support pages for your specific model on how to do this, but it's pretty easy).

If this doesn't solve it then reinstalling OS X might also help, and/or remove any third party kernel extensions you have installed, if any. Try running the system with no peripherals connected like USB drives, connected printers etc - anything hooked up by USB.

Your system log might also give some clues about why the kernel is flipping out.

Edit: high CPU usage on firefox or other browsers is usually plugin related, almost exclusively Flash content. If you have youtube open then expect very high resource usage in Chrome and Firefox due to Flash. It's pretty heavy in Safari too.
 

olletsocmit

macrumors 6502
Original poster
Jun 24, 2010
296
2
USA
you suggested to "remove any third party kernel extensions you have installed" -- what would be an example of a 3rd party extension i may have installed?
 
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