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Macbook Pro Kernel_task using loads of CPU

My MBP has randomly started acting weird.


Symptoms are:


Running VERY slow.

Cooling fan constantly (although not running hot as far as I am aware) - fan kicks in during boot seq

Activity Monitor showing kernel_task eating circa 200% of CPU constantly.


There are no external peripherals connected to the Pro

I've not installed any 3rd party software recently (or at least within a week prior to the issues starting).


I've included a screenshot of the activity monitor User uploaded file

As you can see, the kernel_task process is using a lot of cpu.


I've tried a SMC reset which didn't help at all.


Has anybody got any other suggestions?

Thanks in advance.

MacBook Pro (15-inch Mid 2010), OS X Mountain Lion (10.8.2)

Posted on Oct 7, 2012 4:04 AM

Reply
43 replies

Oct 29, 2012 1:58 PM in response to Linc Davis

I am having the same problem on an early-2009 iMac = took it into AppleStoreGeniusBar and they reinstalled the OS [Mountain Lion] and did their test and all was fine. I have new RAM [8G] and half a T empty on my drive. My kernal-task was running 500mb+ consistently. I've read thru this and other suggestions - the rdoxenham suggestion seems fine but not sure I want to do it yet.


I also saw no smc-Event thing in Console when I ran it. I'm going to log out and use a Standard User account and start in Safe Boot and see but thought I'd add my own iMac related issue.

Jan 17, 2013 7:36 PM in response to SteWilliams

I was having the very same problem on my MacBook Pro 13" Mid 2010. Kernel task showing like 150-200% of cpu usage. Computer basically unusable. I tried many things for many days (like reseting PRAM and SMC) with no success. I am a computer engineer, although I do not usually work on the mac osx platform. The underlying system is very much linux like, which I comfortable with.


To make a long story short, I performed the simple change described in the link above by dmdimon (http://www.rdoxenham.com/?p=259), and walla, just like magic, the problem is gone and has not returned for several days now. I'm not sure sure what this file does, but it is related to the thermal management of the machine.


Anyhow, for what it is worth, it worked for me. Do not be intimidated by the procedure. All you are doing is identifying the exact model description of your machine and then moving one single file from a system directory to your home directory. I highly recommend you try it. My kernel task is now well behaved.

Feb 1, 2013 6:28 PM in response to SteWilliams

I wanted to share an experience I had these days.



If you have not ignore Apple Computer ... but if you want to learn a little about the slutty those authorized are doing feel free to read ...



Who has a macbook pro and are experiencing performance problems, or overheating ... suspect the battery is good. I've had it here and it was only removing the battery that the computer is working again like a charm. Unfortunately Apple recommends battery replacement exclusively on any authorized reseller, but the absurd price of $ 512. It's a way to force the client to replace parts.



Authorized stores that I met seemed to just want to profit from a terrible service, at least here in Brasilia. They even opened my computer and even invented a problem in HD.



I decided to open the computer (now out of warranty) alone and the resolution of the case was simple ... I removed the battery that was preventing proper operation of the system. Ready resolved. There must be an authorized technician to note that in a primary test.



The Apple devices are very efficient, the operating system or speak up. But the brand aims much the American market. There everything comes much cheaper for them, so much so that few people worry about maintenance. They exchange right by a newer one. But here in Brazil, everything gets more expensive.



In my case, the repair including battery replacement and HD would come out for more than R $ 1,200.00. Besides the theft and the lack of preparation, the price is very abusive. In my opinion, whoever does it get worse than Apple itself, but her representatives here in Brazil who uses the fame of the product and want to explore the countrymen, is the knack old Brazilian.



For me good product is a product that works well, but has a sustainable post sale. If you are thinking of buying a computer apple, think well, because when it fails it will be very expensive to get it working again. Or you can venture out and discover the

I wanted to share an experience I had these days.



If you have not ignore Apple Computer ... but if you want to learn a little about the slutty those authorized are doing feel free to read ...



Who has a macbook pro and are experiencing performance problems, or overheating ... suspect the battery is good. I've had it here and it was only removing the battery that the computer is working again like a charm. Unfortunately Apple recommends battery replacement exclusively on any authorized reseller, but the absurd price of $ 512. It's a way to force the client to replace parts.



Authorized stores that I met seemed to just want to profit from a terrible service, at least here in Brasilia. They even opened my computer and even invented a problem in HD.



I decided to open the computer (now out of warranty) alone and the resolution of the case was simple ... I removed the battery that was preventing proper operation of the system. Ready resolved. There must be an authorized technician to note that in a primary test.



The Apple devices are very efficient, the operating system or speak up. But the brand aims much the American market. There everything comes much cheaper for them, so much so that few people worry about maintenance. They exchange right by a newer one. But here in Brazil, everything gets more expensive.



In my case, the repair including battery replacement and HD would come out for more than R $ 1,200.00. Besides the theft and the lack of preparation, the price is very abusive. In my opinion, whoever does it get worse than Apple itself, but her representatives here in Brazil who uses the fame of the product and want to explore the countrymen, is the knack old Brazilian.



For me good product is a product that works well, but has a sustainable post sale. If you are thinking of buying a computer apple, think well, because when it fails it will be very expensive to get it working again. Or you can venture out and discover the slutty of authorized home alone like me!!

of authorized home alone like me!!

Feb 1, 2013 6:29 PM in response to SteWilliams

I wanted to share an experience I had these days.



If you have not ignore Apple Computer ... but if you want to learn a little about the slutty those authorized are doing feel free to read ...



Who has a macbook pro and are experiencing performance problems, or overheating ... suspect the battery is good. I've had it here and it was only removing the battery that the computer is working again like a charm. Unfortunately Apple recommends battery replacement exclusively on any authorized reseller, but the absurd price of $ 512. It's a way to force the client to replace parts.



Authorized stores that I met seemed to just want to profit from a terrible service, at least here in Brasilia. They even opened my computer and even invented a problem in HD.



I decided to open the computer (now out of warranty) alone and the resolution of the case was simple ... I removed the battery that was preventing proper operation of the system. Ready resolved. There must be an authorized technician to note that in a primary test.



The Apple devices are very efficient, the operating system or speak up. But the brand aims much the American market. There everything comes much cheaper for them, so much so that few people worry about maintenance. They exchange right by a newer one. But here in Brazil, everything gets more expensive.



In my case, the repair including battery replacement and HD would come out for more than R $ 1,200.00. Besides the theft and the lack of preparation, the price is very abusive. In my opinion, whoever does it get worse than Apple itself, but her representatives here in Brazil who uses the fame of the product and want to explore the countrymen, is the knack old Brazilian.



For me good product is a product that works well, but has a sustainable post sale. If you are thinking of buying a computer apple, think well, because when it fails it will be very expensive to get it working again. Or you can venture out and discover the

I wanted to share an experience I had these days.



If you have not ignore Apple Computer ... but if you want to learn a little about the slutty those authorized are doing feel free to read ...



Who has a macbook pro and are experiencing performance problems, or overheating ... suspect the battery is good. I've had it here and it was only removing the battery that the computer is working again like a charm. Unfortunately Apple recommends battery replacement exclusively on any authorized reseller, but the absurd price of $ 512. It's a way to force the client to replace parts.



Authorized stores that I met seemed to just want to profit from a terrible service, at least here in Brasilia. They even opened my computer and even invented a problem in HD.



I decided to open the computer (now out of warranty) alone and the resolution of the case was simple ... I removed the battery that was preventing proper operation of the system. Ready resolved. There must be an authorized technician to note that in a primary test.



The Apple devices are very efficient, the operating system or speak up. But the brand aims much the American market. There everything comes much cheaper for them, so much so that few people worry about maintenance. They exchange right by a newer one. But here in Brazil, everything gets more expensive.



In my case, the repair including battery replacement and HD would come out for more than R $ 1,200.00. Besides the theft and the lack of preparation, the price is very abusive. In my opinion, whoever does it get worse than Apple itself, but her representatives here in Brazil who uses the fame of the product and want to explore the countrymen, is the knack old Brazilian.



For me good product is a product that works well, but has a sustainable post sale. If you are thinking of buying a computer apple, think well, because when it fails it will be very expensive to get it working again. Or you can venture out and discover the slutty of authorized home alone like me!!

of authorized home alone like me!!

Feb 28, 2013 8:38 AM in response to SteWilliams

Just resolved this on my 2-week old 13'' MacBook Pro. After wasting hours trying to troubleshoot using forums I reached out to a friend who specialized in Mac support... his response kind of ****** me off but turns out he was right.


"kernel_task is indexing the drive. just leave it alone"


I let it run overnight and woke up to a quiet fan and kernel_task pegging to -80% cpu instead of +300% as it had the night before (thanks to Patrick McNally if you ever read this).


The symptoms I was experiencing:

- At startup the fan would slowly increase to 100% and stay there.

- Startup took a long time.

- Applications where slow to open and work with.

- Activity monitor showed kernel_task using over 300% of CPU.

- CPU was not overheating.


2x SMC Reset did nothing.

2x PRAM Reset did nothing.


Hope this is helpful.

Apr 17, 2013 11:04 PM in response to SteWilliams

mac pro kernal task high fan speed:


This seems to be an intermittent process normal for macs.


I panicked when mine did this. However, after pulling my hair out googling for an answer, I found something quoted from an Apple engineer: "the machine is cateloging itself, just let it run". Not Spotlight, btw, rather a normal process the machine performs from time to time.


So, after restarting, uplugging, resetting...pulling out the HD and seeing if I could detect heat, backing up everything, I just gave up and took the advice. The next day it stopped. It went for months without a problem (it's doing it now, again, hence my looking for more answers...).


I downloaded a utility call iStat Menus (there is a free trial), so I could monitor temp sensors in the machine. Everything, except fan speeds (exhaust, HD/expansion) is performing at a normal range.


I guess if I bought a Mercedes and it made a loud noise while driving I would panic. It'd be nice if Mr. Apple could tell us of 'issues' like this. I know I would like Mr. Mercedes to.

Aug 3, 2013 4:20 AM in response to SteWilliams

I figured out the probelm on my machine, a mid 2012 MBP model. I believe the problem I had (and occassionally still have) is that charging the machine causes the battery (or something near it) to heat up, which in turn causes the kernetl_task process to kick in and consume too much CPU. On my machine, it jumped to as much as 500%!


The solution in this case is very simple: disconnect the charger. The kernel_task process goes back to under 5% in less than 30 seconds. I can reconnect it after 10 minutes or so to continue charging. If it happens again in the same recharge cycle, repeat. Annoying but easy fix.


Note that I only experience this issue when my battery drops low enough (say, under 30%) that it needs a lengthy recharge period.


Hope that helps.

Macbook Pro Kernel_task using loads of CPU

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