kernel_task using over 100% cpu. Any simple fixes??

Please read this whole message before doing anything.

This procedure is a diagnostic test. It’s unlikely to solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.

The purpose of this exercise is to determine whether the problem is caused by third-party system modifications that load automatically at startup or login. Disconnect all wired peripherals except those needed for the test, and remove all aftermarket expansion cards. Boot in safe mode and log in to the account with the problem. The instructions provided by Apple are as follows:

• Be sure your Mac is shut down.
• Press the power button.
• Immediately after you hear the startup tone, hold the Shift key. The Shift key should be held as soon as possible after the startup tone, but not before the tone.
• Release the Shift key when you see the gray Apple icon and the progress indicator (looks like a spinning gear).

Safe mode is much slower to boot and run than normal, and some things won’t work at all, including wireless networking on certain Macs.

The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.

Test while in safe mode. Same problem(s)?

After testing, reboot as usual (i.e., not in safe mode) and verify that you still have the problem. Post the results of the test.

It happens because of overheating, which causes the logic board to throttle the CPU. See the thread linked below for some user experiences.

kernel_task hogging my CPU, over 300%: Apple Support Communities

You could have a faulty temperature sensor, or some other logic-board fault.

Linc Davis wrote:

It happens because of overheating, which causes the logic board to throttle the CPU.

That's odd.

Because of overheating… the software ramps up the Kernel Task forcing the CPU to work harder at doing nothing?

Wouldn't the software just do what it's supposed to do, and then, when I quit all the apps, do nothing and get cooler because it's doing nothing?

When KT is running wild, I can quit everything else, and KT will run through the night, several days, forcing the CPU to run 50% on both processors. I can't kill the process. But it's not like it's solving or fixing or anything. It's "throttling" as in beating the CPU up, fore sure! But the only thing it's slowing down is me.

I had the same problem with my MBP 13" early 2011 , and thank god it got fixed by disconnecting the battery which was already dead since a month ago due to high temp :(

Hope this may help anyone in the future

Hi AmdSyam, you deffinitely helped me!!

I too had a faulty battery that was still connected, and my macbook pro became really slow, spinning beachball etc. after disconnecting the battery everythings back to normal.

Thanks a million!!!

Djan Wong

Hi All,

I am new to Mac and have a brand new Macbook Air which is three weeks old. Just today the PC began to slow extremely and would run the fan from start up using only firefox. I eventually located Kernal_task running at over 300%.

Simple key strokes take 10-30 seconds to appear. The PC is completely unusable.

Does this mean i need to have a warranty repair, same as DMHK in this thread? >> https://discussions.apple.com/thread/3693588?start=0&tstart=0

Just for the record, kernel_task using a bunch of CPU doesn't necessarily have anything to do with the battery (it actually surprises me that it does).

Here's a handful of things off the top of my head that I've encountered which would cause kernel_task to run amok:

• Spotlight indexing away at attached devices
• Spotlight indexing away on an NTFS partition in case you Boot Camp
• Heavy torrent downloading
• Finder doing something on network shares (unmounting them would stop)
• Finder doing something on mounted DMGs (e.g. today, a Java update)

There are more scenarios which I can't recollect ATM, but the commonality here seems to be I/O of some form, which kinda makes sense to me that something called kernel_task would be involved in, although it doesn't seem sane the amount of CPU used by the kernel in some of these cases.

All scenarios, except the torrenting one, sometimes get "stuck", that is kernel_task will seemingly indefinitely stay at 100, 200, 300, or 400% CPU. And clearly, in the "stuck" cases, such as the Java update DMG simply being mounted and causing kernel_task to use 100% CPU until it's unmounted, something must be broken somewhere.

The bottom line, anyway, as this behavior has been with me ever since I got my first Mac running Lion, and doesn't seem to get fixed, whenever I encounter this, the first thing I do is try to find a network share or mounted volume to unmount. It usually "fixes" it.

I found a temporary Solution for the kernel_task Problem.

(If you dont want to plug the power cable on and off.)

I bought a mini fan for about 10 € put it next to my macbook pro and turned it to the direction where the battery is. Wait a minute and watch in your activity monitor how the kernel_task slows down from 200% to 4,3 or something like that.. The only thing whats annoying is the sound wich comes from the fan. But thats a small price to pay :-)

I think another solution would be to completely delete your hardrive and install Snow Leopard.

But im to lazy to try that out so i just stick with my fan solution.

I have this setup for a year now and never had any kernel_task overheating (or whatever you call it) problems again. (even in games with much cpu usage)

What does it mean when kernel_task cpu % usage dips back down into single digits in safe mode?

Seems to be related with AppleHDA Audio Codecs (old ones from OS10.8 work), that's why when you guys unplug the headphones the CPU level cames to normal levels. This problem is still not solved.

I've been chating with some Apple amployees about it and they say it's a Maverick's problem. I've said them that so many people is having this problem in Apple's official forums and they reccommend me to say you guys to open a "Feedback Bug Report" in Apple's website: http://www.apple.com/feedback/

They told me that in the forums where you guys explain this issue, they don't read it them all, and the worst of all, apple enginyeers don't read them. So, i reccommend you to open a Bug Report in order to let them know about this problem and giving them enough information to solve it.

Thanks