Fix for KERNEL_TASK cpu usage

[gryffin]

Hi

 

So a lot of people have kernel task running at 100% CPU, making the system completely unusable, I also had this issue and followed all the suggestions of pulling out all unnecessary hardware, remove all usb devices and reinstall a vanilla osx, none of these worked for me although you should probably still try them.

 

I noticed it happened during installing, disk utility etc, all these have one thing in common, they use CPU. I then read around and saw that any real macs that had this issue were macbook airs that were overheating. I rebooted (quickly!) into the BIOS and went to pc health status, my cpu temp was 90oc!

 

Turned out that my heatsink fan (which needs to be a certain direction due to the way it works) was on wrong. Kernel_task has some routine it runs when the cpu is hot, which causes it to spike so high and remain high.

 

So the moral of this story is, if you have KERNEL_TASK cpu usage problems, QUICKLY reboot and check your CPU temp in your BIOS (don't use software temp sensors as these can be inaccurate - even more so on OSx86)

 

Post here if this solved the issue for you. Hope it helped someone, my cpu is now running around 40oc idle with no issues