How to solve kernel_task high CPU usage?

Definition = a solution

@Ideaman924 has a very valid point - messing with system files could be a recipe for a disaster.

I had 200-300% kernel_task CPU usage and very sluggish performance on my MBPro 13". It's a problem that just started recently - maybe when I did the OSX 10.8 -> 10.9 upgrade?

In any event, my approach was to:
1) fire up the Activity Monitor (CPU tab)
2) one by one, unplug everything that was plugged into my MBP

What I found is that driving a Dell 24" monitor with a Rocketfish video adapter and off brand HDMI cable was cause for about 30% of the problem. Don't know if its just the demands of HDMI or the non-apple adapter, but using VGA instead (with an Apple branded adapter) freed up a lot of CPU cycles.

I was still pretty high on the CPU use, however, so I shutdown my Fusion 7/Win 7 virtual machine. Voila! The combination of the HDMI and no Virtual Machine running got kernel_task down to 3-5% total - with NO SYSTEM FILE CHANGES.

Now, since I want to use my virtual machine and get my display back to HDMI resolution, I'll have to see if I can remember what might have changed in the last 1-2 weeks or so when all of this started happening... At least now I know where to start looking for the root cause...

EasyGoing1 said:

OK, so I have a 2013 late model MBP, and I have been having this issue for some time now ... In my case, when I run the hardware diagnostics, it says that I *MAY* have a faulty PMU or PCU or power whatever logic board thing-a-ma-jig ... However, I had to replace my screen a few months back because I dropped the MBP and cracked my screen, and the screen I bought from ebay had some of the wires cut and I didn't read the fine print before I made the purchase (it was only $200 and other than the wires being cut (not the video cable, but the other ones) it works great! But since I put this screen in, I've been having the high CPU utilization in my kernel_task process and my MBP ran slower than molasses ...

Well, after much experimentation, research, trial and error, I finally solved the problem... here is what you need to do:

Open up terminal (If you don't know what that is, you have no business doing this in the first place)...

type (or copy and paste from here):

Code:

sudo mv /System/Library/Extensions/AppleSMCLMU.kext ~

that will move it to your parent home folder

Reboot!

I also have AppleIntelCPUPowerManagementClient.kext and NullCPUPowerManagement.kext in my home folder, but I'm 99.999% positive that the problem went away after moving that SMCLMU kext file out of the extensions folder and re-booting. I believe that is the file that reports the mis information to the kernel which then freaks the heck out for some reason - in my opinion, the way OSX responds to a bad sensor is a very poor way to respond to a bad sensor ... sure, lets make the computer almost unusable so that the user will pay us to fix it for them ... there are times when hardware can be faulty, yet there is no risk to the computer at all, it doesn't mean that your laptop will never reach temperature levels which that sensor monitors which will put your laptop in danger ... in fact, in my case, the sensor readings were pinging at -128 degrees ... you'd think that Apple would realize that -128 is indicative of a faulty sensor especially when the other sensors are reading normal temperatures ... so why dumb down the computer when it's obvious that the sensor isn't actually providing a reading which indicates danger for the hardware... that the sensor itself is actually the problem so no need to go to extremes and make the computer run slower... sensors are there as a secondary watch over the hardware, the user being the first ... so again ... why design an operating system to run slow when a sensor has merely gone bad? Could you imagine if car manufacturers made your car go no faster than 20 miles per hour because of a bad o2 sensor???? It's a piss poor design call on Apple's part and they really need to fix it.

Good luck everyone!

Mike Sims

----------



I forgot to mention that I've been using my MBP for over 15 hours now since implementing the solution I posted without any slow down issues or high CPU utilization what so ever ... that is a world record for this MBP as I have been dealing with this problem for MONTHS ... it's like having a new mac now.

Click to expand...

I did this to my MacBook 2010 and it calmed down a ton..
The Fan was crasy, and the machine itself was crasy hot. Now its calm and the fan works when i put a load on the CPU... How come this file from apple cause issue for me?
Im realy thankful i found this thread!!!

Persona said:

I followed these steps from above and it worked perfectly. Resetting the PRAM and SMC did not solve the issue.

The battery is registered and I "do not" have a high fan issue.

FYI,
MacBook Pro 2011
Replaced battery from original 7700mAh ? to an Anker 5400mAh




1. Go to About this mac under the apple in the upper left and click on More info
2. Click on system report
3. make a note of what it says after Model Identifier
4. go to your master drive – System -Library – Extensions – IOPlatformPluginFamily.kext -Contents – Plugins – ACPI_SMC_PlatformPlugin.kext – Contents – Resources – find the name from step 3 and move it to a folder that you can find again if needed.
3. Restart and you’re done

Click to expand...

I completed step 3. It said "MacBookPro9,2". The last MacBookPro in the list from step 4 is "MacBookPro8_3.plist". What is the reason/fix for this? I followed the instructions, "right-clicked" on each .kext item to bring up contents. Did I somehow do this wrong?

I have a 13" mid 2012 model.

Tongue in Cheek Solution

I'd like to first say that as irony would have it ... literally 10 minutes after happily posting my kext file solution ... the problem came back. I was going to post that right away, but I decided to wait until I finally conquered this beast of a problem.

Needless to say, I was VERY frustrated and didn't know what to do next ... so I decided that maybe I could somehow just replace the sensors and be done with this issue all together. But upon googling around for anything sensor related for the MBP, I pretty much came up with a big goose egg.

So I started a post on fixit.com asking if the sensors can be replaced, and what I got was someone who - in my opinion - was oversimplifying the problem ... since in my case, the problem didn't manifest until AFTER I had replaced my screen, he felt that maybe the sensors were being shorted out for some reason - as in the re-assembly of the case was somehow botched or maybe something unexplainable simply happened and for whatever reason, the sensors were being shorted out and that I should try taking the case apart and use an external monitor to see if the problem persists.

I thought he was crazy.... so I did NOT take his advice ... HOWEVER ... about 4 days later, I was working on the MBP in my bedroom, sitting up in bed and I noticed that I went a full day without the problem happening. Then I had to re-position the laptop so that I could do something, and the fans kicked into high gear and the laptop slowed down again ... "OH BOY ... here we go again..." I dealt with it like that for a few hours, then placed the laptop back onto the bed where it was before, and within 5 seconds, the problem stopped ... "what did I do? ... what was different?" ...

As it turned out, placing the laptop on an incline of about 10 degrees where the rear of the MBP is higher than the front, the problem went away... but if I set the laptop flat and level, the problem kicked in.

So I of course immediately thought of the crazy guy who told me to take it apart again and do those tests ... so a few days later, I busted out the tools and took it apart ... But I didn't run it on an external monitor ... what I did do, was tighten the screws on the display hinges because a couple of them became loose over the months, and I cleaned the motherboard really well with some q-tips, 98% rubbing alcohol and distilled water in a 50/50 solution ... after that, I got as much dust out of the fans as I could get.

When I re-assembled everything SECURELY and CAREFULLY ... then fired it up ... It ran like a dream, and i've not had a single kernel_task high CPU problem since. And that was FIVE DAYS ago now. I've run it on a flat surface, I've run it sitting on a pillow ... I've run it everywhere and put it through the paces, and I even ran the hardware diagnostics - which originally told me I had faulty power management hardware but now says I have no problems at all.

It's nice to FINALLY have my original MBP back in full swing.

I hope this helps someone else out there who has a few holes in their walls about the same shape as their skull .... I can finally patch mine up.



Mike

Monitoring the Hall Monitor...

schmidtl said:

@Ideaman924 has a very valid point - messing with system files could be a recipe for a disaster.

Click to expand...

I'd just like to comment on these KINDS of comments ... in general (i'm not picking on you specifically schmidtl)...

I've been doing I.T. professionally for 20 years now, and have been a successful independent consultant for about 5 years now, and it's been my experience that the "average" computer user isn't going to be googling around for solutions to their problem, then SLOWLY attempting to fix it by issuing SUDO commands and moving system files around... most of the time, those kind of people are going to be calling for some support and getting a professional to help them.

The ones who are too stupid to know the difference between a path and an icon will sufficiently screw up their computer and ... we'll ... they will be calling a professional to help them....

I've noticed that forums like this one seem to have an unusually high number of "alarmists" who seem to always want to pipe in and warn people that the above listed - whatever it is - could be hazardous to your computer... yadda ... yadda ... yadda ... But what it really boils down to - in my opinion ... is that these people like to hear - er - read themselves say something important and smart ... in other words, its more of an ego thing for them than it is a sincere concern that some poor sap may eff up his computer.

I RARELY post in forums ... maybe I should participate more, as I do use the forums A LOT to find answers to questions I have ... I am just typically one of the many who read and never respond. The only reason I participated in this thread was because there are no solid solutions to the problem that I and many others have been suffering from. I tend to think that many people who have been having this issue end up either junking their laptop or paying for expensive mother board replacements etc.

But I digress...

My point here, is that before you go clicking on the quote button to add your two cents about how dangerous something might be for someone ... realize something first:

1) MOST Mac users today have something called a Repair Boot Partition... if they found and then attempted to implement a solution that screwed up their mac, they can probably just as easily find out that they can boot into the repair partition and undo whatever they did.

2) over 90% of the people who WILL attempt terminal access and sudo their commands are already familiar with the terminal environment and are comfortable with the basics sufficiently enough to know what they are doing and therefore, how to undo it.

3) The odds that someone will actually read your post and said, "OH ... I could screw up my computer if I do this? Well then ... thank you hall monitor ... I won't even attempt to fix the problem thats been keeping me awake at night for over a week now ... thank you for saving me!"

4) Have you ever read a post where someone described in detail what to do in Terminal ... WITHOUT already giving a warning to the noobs? So then isn't your alarmist response ... really just redundant and unnecessary?

I know there are a lot of you guys out there who squeeked through high school with straight A's .... no friends .... and even graduated a virgin ... and I know you get all excited when you think you can help people by boldly pontificating your vast and infinite computer wisdom in these forums ... but let me tell you that for every one of you, there are probably thousands of us shaking our heads knowing that your fishing for ego boost and we just sit quietly by - not saying anything in the interest of professional courtesy...

But honestly ... the next time you're tempted to be the hall monitor of self assist problem solving ... do all of us a favor and just keep scrolling ...

Mike

Source of problem found!

So last night, I found the source of the problem... I spilled a little water in my keyboard, so I flipped the MBP upside down and turned it off immediately to try and prevent any water from reaching the logic board.

I then proceeded to take it apart and the logic board out, where I thoroughly dried it and cleaned it with a little rubbing alcohol.

When I re-assembled and booted, the problem came back, only this time, this is what I discovered...

I had to replace the retina display on this late model 2013 MBP around February of this year, because I dropped the MBP and cracked the screen that came with it. The screen I ordered off of eBay had cut wires on it. the display cable was intact, but the isight wire was gone. SO, what I did was retain the isight wire harness from my old screen, and used it. And as many of you know, that entire harness is fed through the left hinge of the laptop so it was relatively easy to swap out the harness, leaving the iSight camera cables DISCONNECTED as there are something like 10 wires in the isight cam portion of the harness which are almost too small to see with 43 year old eyes, but worse than that, they are not marked ... so getting them to line up with the portion of the wire that was already cut on the new screen was going to be an impossible task ... so I left the isight portion of the harness cut and just resting there. The other three wires which are antennas for the Airport card, were intact so I didn’t mess with those at all.

Here are some pics showing the cable and where it is connected at the logic board. The portion of the entire wire harness that was at fault is highlighted in pink.




But what I discovered last night was that the end of that wire coming from the motherboard to the iSight cam was hanging out in the open exposed ... and now it apparently had small frays on the ends and were in fact shorting one another out.

So I decided to remove that portion of the harness and disconnect it from the motherboard and WALLA! problem solved! No more crazy high cpu using kernel_task.

I hope this post helps someone who might be going through something similar.

Yessss

fantasticbobski said:

Okay, I seem to have solved the kernel_task PCU drain using this method I stumbled across on the web.

1. Go to About this mac under the apple in the upper left and click on More info
2. Click on system report
3. make a note of what it says after Model Identifier
4. go to your master drive – System -Library – Extensions – IOPlatformPluginFamily.kext -Contents – Plugins – ACPI_SMC_PlatformPlugin.kext – Contents – Resources – find the name from step 3 and move it to a folder that you can find again if needed.
3. Restart and you’re done
I hope this helps.

Only problem now is the battery won't register, new or old and the fan is running 100% of the time.

Click to expand...

This solution totally works. Thank you so, so, so, so much!!!

Just see the difference in the attached images (before & after).

kernel_task, no IOPlatformPluginFamily.kext

Hi,

I try to fix my Kernel_task problem, but I do not have this file everybody is tracking about: IOPlatformPluginFamily.kext

In my extension folder I have only these files:

ArcMSR.kext
ATTOCelerityFC8.kext
ATTOExpressSASHBA2.kext
ATTOExpressSASRAID2.kext
CalDigitHDProDrv.kext
HighPointIOP.kext
HighPointRR.kext
PromiseSTEX.kext
SoftRAID.kext

Somebody familiar with this problem?

Other info about my Mac that might be useful:

Model Name: MacBook Pro
Model Identifier: MacBookPro9,2
Processor Name: Intel Core i5
Processor Speed: 2,5 GHz
Number of Processors: 1
Total Number of Cores: 2
L2 Cache (per Core): 256 KB
L3 Cache: 3 MB
Memory: 4 GB
Boot ROM Version: MBP91.00D3.B09
SMC Version (system): 2.2f44
Serial Number (system): C1MM86FADTY3
Hardware UUID: F8BBE78A-ED51-5CB8-858D-A7629CD5B987
Sudden Motion Sensor:
State: Enabled

TIA!

Same Issue at rallyrelmar

Hey:

I have same results as rallyrelmar, with the addition of 'hp_io_enabler_compound.kext' in the list.

Just some more info that may be helpful for anyone who is smarter than me...

Thanks so much...

fantasticbobski said:

Okay, I seem to have solved the kernel_task PCU drain using this method I stumbled across on the web.

1. Go to About this mac under the apple in the upper left and click on More info
2. Click on system report
3. make a note of what it says after Model Identifier
4. go to your master drive – System -Library – Extensions – IOPlatformPluginFamily.kext -Contents – Plugins – ACPI_SMC_PlatformPlugin.kext – Contents – Resources – find the name from step 3 and move it to a folder that you can find again if needed.
3. Restart and you’re done
I hope this helps.

Only problem now is the battery won't register, new or old and the fan is running 100% of the time.

Click to expand...

hi, i reached here and dont know what to do next, where is the Contents after i got this IOPlatformPluginFamily.kext

Thank You!

EasyGoing1 said:

So last night, I found the source of the problem... I spilled a little water in my keyboard, so I flipped the MBP upside down and turned it off immediately to try and prevent any water from reaching the logic board.

I then proceeded to take it apart and the logic board out, where I thoroughly dried it and cleaned it with a little rubbing alcohol.

When I re-assembled and booted, the problem came back, only this time, this is what I discovered...

I had to replace the retina display on this late model 2013 MBP around February of this year, because I dropped the MBP and cracked the screen that came with it. The screen I ordered off of eBay had cut wires on it. the display cable was intact, but the isight wire was gone. SO, what I did was retain the isight wire harness from my old screen, and used it. And as many of you know, that entire harness is fed through the left hinge of the laptop so it was relatively easy to swap out the harness, leaving the iSight camera cables DISCONNECTED as there are something like 10 wires in the isight cam portion of the harness which are almost too small to see with 43 year old eyes, but worse than that, they are not marked ... so getting them to line up with the portion of the wire that was already cut on the new screen was going to be an impossible task ... so I left the isight portion of the harness cut and just resting there. The other three wires which are antennas for the Airport card, were intact so I didn’t mess with those at all.

Here are some pics showing the cable and where it is connected at the logic board. The portion of the entire wire harness that was at fault is highlighted in pink.

Image
Image

But what I discovered last night was that the end of that wire coming from the motherboard to the iSight cam was hanging out in the open exposed ... and now it apparently had small frays on the ends and were in fact shorting one another out.

So I decided to remove that portion of the harness and disconnect it from the motherboard and WALLA! problem solved! No more crazy high cpu using kernel_task.

I hope this post helps someone who might be going through something similar.

Click to expand...

Thank you. My kernel_task process was using over 300% of my CPU. I was about to delete system files, mess around in the terminal (taking a huge risk because I had no ide what I was doing), but then I saw this post. I decided to clean and blow out my logic bored and it worked perfectly! I had never cleaned my MBP so I guess I had this coming.

I never post on these kinds of forums but I wanted to thank you for this very simple fix. Hopefully others with this problem try cleaning their MBP first.

faulty sensor

hi folks,
I stumbled onto this thread because I got the same issue immediately after Apple had replaced my logic board!!

I have a 2011 15" MBP which seem to have a common issue with the graphics card. Even though I bought the laptop second hand from eBay - Apple agreed to replace the logic board because they could tell from the serial number that it had been originally bought at an Apple store. This means that they are bound by consumer law to fix faults with the hardware.

After they replaced the board, I saw the 'kernel' issue of maxing out CPU. I considered trying one of the teqniques discussed here, but thought the obvious thing was to take it back to Apple ( this was the same day that I'd picked it up after the initial repair ).

They acknowledged that the new issue ( maxed out CPU, fans at high speed, crippled performance ) was due to a faulty sensor. I guess the system thinks that it is overheating and so throttles the CPU. The are now replacing the Logic board for the second time. Let's hope this one works.

The moral: even if you don't have Apple Care, or your system is not within warranty, Apple may provide FREE repairs if your computer was originally purchased from them.

------- 8<---- snip -------- 8<-------
... there are times when hardware can be faulty, yet there is no risk to the computer at all, it doesn't mean that your laptop will never reach temperature levels which that sensor monitors which will put your laptop in danger ... in fact, in my case, the sensor readings were pinging at -128 degrees ... you'd think that Apple would realize that -128 is indicative of a faulty sensor especially when the other sensors are reading normal temperatures ... so why dumb down the computer when it's obvious that the sensor isn't actually providing a reading which indicates danger for the hardware... that the sensor itself is actually the problem so no need to go to extremes and make the computer run slower... sensors are there as a secondary watch over the hardware, the user being the first ... so again ... why design an operating system to run slow when a sensor has merely gone bad? Could you imagine if car manufacturers made your car go no faster than 20 miles per hour because of a bad o2 sensor???? It's a piss poor design call on Apple's part and they really need to fix it.

Good luck everyone!

Mike Sims

----------



I forgot to mention that I've been using my MBP for over 15 hours now since implementing the solution I posted without any slow down issues or high CPU utilization what so ever ... that is a world record for this MBP as I have been dealing with this problem for MONTHS ... it's like having a new mac now.

Click to expand...

With faulty engine sensors in cars, that's almost exactly what happens in most cases (although limp home mode doesn't make it quite as bad as 20mph), if the o2 sensor returns faulty readings, the engine management system can't make accurate calculations as to what the fuel/air mixture should be, so uses a safe value, running the engine richer and limiting the revs, which will get you to a garage (albeit slowly - my car does this on a regular basis...).

I'm guessing the same reason applies here too; If its getting a faulty sensor reading, the SMC would play it safe by making the assumption that as it doesn't know the temperature, that a worst case scenario has occurred and there is no cooling at all (like a total failure of the thermal compound that conducts heat away from one of the chips, for instance - this being the case, other sensors would't see a temperature increase), and spins up all the fans, and would throttle the CPU. If I remember correctly, Intel CPUs automatically slow themselves down when they get too hot (I think that was introduced back in the Pentium days, unlike some of the older AMD pentium-compatible chips of that era that used to just catch fire!). In a worst case scenario (more than a certain number of sensors bad, and no fan speed signal, the SMC should just power everything off)

Similar problems here...

Kernel_task taking all the cpu, fan running like crazy, and apple hardware test returning an error that seems to be referred to an ambient temperature sensor...

Tried to follow this trick, but there's no file for macbook pro 9,2... I'm quite disappointed now.

I wish I could make my mac usable again while I wait to repait this damn sensor... Btw, does anybody have a clue where this sensor is located?

Any solution?

EasyGoing1 said:

I've noticed that forums like this one seem to have an unusually high number of "alarmists" who seem to always want to pipe in and warn people that the above listed - whatever it is - could be hazardous to your computer... yadda ... yadda ... yadda ... But what it really boils down to - in my opinion ... is that these people like to hear - er - read themselves say something important and smart ... in other words, its more of an ego thing for them than it is a sincere concern that some poor sap may eff up his computer.

Click to expand...

So I'm an alarmist, huh? And schmidtl is one too. However

EasyGoing1 said:

I digress...

Click to expand...

You have no idea what these kext files do. And since you mentioned

EasyGoing1 said:

1) MOST Mac users today have something called a Repair Boot Partition... if they found and then attempted to implement a solution that screwed up their mac, they can probably just as easily find out that they can boot into the repair partition and undo whatever they did.

Click to expand...

Okay, yeah, this is really dandy, but it's not called Repair Boot Partition. It's called Recovery HD or Internet Recovery HD. Having said this, you must've learned windows when you've

EasyGoing1 said:

been doing I.T. professionally for 20 years now

Click to expand...

or not learned anything at all. Second off, what if they don't know the recovery partition? I've seen kids go and just copy terminal lines from the internet and paste them into their Terminal.app. Having said this, last week I had to fix this kid's Mac, and he said he had copied some lines from a 'internet forum'. And the kid in question didn't have any knowledge of 'Recovery HD'. He even Googled his problem and posted his problem in the same forum.

So...

EasyGoing1 said:

2) over 90% of the people who WILL attempt terminal access and sudo their commands are already familiar with the terminal environment and are comfortable with the basics sufficiently enough to know what they are doing and therefore, how to undo it.
4) Have you ever read a post where someone described in detail what to do in Terminal ... WITHOUT already giving a warning to the noobs? So then isn't your alarmist response ... really just redundant and unnecessary?

Click to expand...

Is invalid. Nice knowing now.

EasyGoing1 said:

3) The odds that someone will actually read your post and said, "OH ... I could screw up my computer if I do this? Well then ... thank you hall monitor ... I won't even attempt to fix the problem thats been keeping me awake at night for over a week now ... thank you for saving me!"

Click to expand...

Maybe this would be different if the user in question posted a different solution for the dangerous solution. The OP will attempt the solution posted by US, not idiots like you.

EasyGoing1 said:

do all of us a favor and

Click to expand...

shut up.

To cap up, you're a guy who has no business in Mac society, or any society at all if concerned.

-------Okay, let's stop reading my dispute with EasyGoing1 and let's focus---

1. This kext file is related to SMC, therefore if you move/delete/edit it, the SMC will not work, meaning some sensors will not therefore. It might lead to overheating because a)your SMC cannot find current temp readings and b)the fans will not work because SMC will think the temp is fine and put the fan at default level, 2000 rpm, which will cause overheating and thus make your computer unusable. Why unusable?

The computer will keep overheating and the sensors won't detect it. If you are on a surface where heat ventilation is bad, your computer might have a meltdown (of the CPU, logic board, et cetera), that is, because it will not force shutdown to stop overheating. You will have a nice shiny aluminum paperweight, with crystal clear glass that will show your reflection (or not if you cracked it)

SO: DO NOT CHANGE SYSTEM FILES.

2. Try
a) putting your Mac at a flat surface
b) making sure high-intensive apps are off (iMovie, Handbrake, Adapter, etc.)
c) disconnect all external connectors like USBs and FireWire (now obsolete), Thunderbolt, etc.
d) try SMCFanControl (this is relatively not dangerous, but please, be careful! setting 6200 rpm or so will wear out your fan in the long run, so don't be reckless)
e) if you have a laptop cooler, use it

Kernal Task

Thanks for this info. Just took care of the problem. Hopefully this will tame the beast.

I do have one question that hopefully someone can answer. I moved the listed file to a folder on the desktop. Is this something that I would really need to keep, and if so, how do I restore the file to the programming menu?

Thanks for the response and forgive my lack of knowledge. It comes from years of using Windows.

Alternative to disabling cpu throttling via kernel task

I've also had this problem, but was reluctant to mess with the System files as described. A prolonged bout of Googling lead me to this post at ycombinator. I deleted the files in the systemstats directory and rebooted. After a burst of kernel task activity (presumably repopulating the database files in the directory) it settled down to virtually nothing and has stayed there all day. YMMV, of course.

fantasticbobski said:

Okay, I seem to have solved the kernel_task PCU drain using this method I stumbled across on the web.

1. Go to About this mac under the apple in the upper left and click on More info
2. Click on system report
3. make a note of what it says after Model Identifier
4. go to your master drive – System -Library – Extensions – IOPlatformPluginFamily.kext -Contents – Plugins – ACPI_SMC_PlatformPlugin.kext – Contents – Resources – find the name from step 3 and move it to a folder that you can find again if needed.
3. Restart and you’re done
I hope this helps.

Only problem now is the battery won't register, new or old and the fan is running 100% of the time.

Click to expand...

After downgrading from Yosemite (because of its UI slowness), my MBP still felt somehow slow (much better than in Yosemite, though). The solution posted above cured everything (I stumbled upon on Apple forums) and it worked like charm!

I was also struggling with a problem on my MacBook Pro. A while ago my harddrive crashed. I replaced it with an SSD, but shortly after this I noticed the same high CPU problem as described by others in this thread. I have also moved the system file and it seems to have solved the problem!

The reason I am taking the effort to post this message is that I am entertained by the "experts" warning not to touch the system files, but who are not giving any proper solution after this. Yes, I do understand system files are not something you should mess with if you're unfamiliar with the consequences, but then giving a "solution" where it is suggested that I place my mac on a flat surface and unplug all external devices?!?? I'm sorry, but is that supposed to be helpfull? Do you really think the avarage person reading this did not think of doing that? Okay, maybe I am overestimating the avarage Mac user's intelligence, but stil...

In my case, the MacBook I am referring to had a new SSD harddrive with a clean install of OSX. No heavy software has even been installed yet, no external devices plugged in other then the power cord and I have already tried reinstalling and resetting everything. Twice.

I have just moved this system file that I should definitively not move according to the so called experts here. So far it worked exactly as described! Problem solved! If you do not hear from me again in this tread, then I did also not encounter any problems later.

(Maybe you guys should focus on why this sollution works instead of fighting over wether it is safe to execute it)

monster161815 said:

hi folks,
I stumbled onto this thread because I got the same issue immediately after Apple had replaced my logic board!!
...

After they replaced the board, I saw the 'kernel' issue of maxing out CPU. I considered trying one of the teqniques discussed here, but thought the obvious thing was to take it back to Apple ( this was the same day that I'd picked it up after the initial repair ).

They acknowledged that the new issue ( maxed out CPU, fans at high speed, crippled performance ) was due to a faulty sensor. I guess the system thinks that it is overheating and so throttles the CPU. The are now replacing the Logic board for the second time. Let's hope this one works.

Click to expand...

So I have been having ongoing issues since my last repair - fans pulsing on and on, kernel task running at 300% and everything running super slowly.

I ran a hardware test to see if there were any faulty sensors, and turns out one of my fans was non-functioning. I popped open my case, pressed firmly on all the connections of the non-functioning fan (had computer running) and the fan kicked in. I opened it up and everything was working perfectly. (I did accidentally weld one of my tools because of the active circuit - always disconnect your battery before doing anything like this. I was lucky!)

This kernel_task high CPU usage can be a lot of things. If deleting/moving some system files solved your problem, then great; if not, there are many other causes for this behavior.

I have a 2007 MBP that had a cooling fan die a year ago. One day I noticed my computer was slowing to a crawl, the fan was running at high speed like a jet engine, and from Activity Monitor I saw this kernel_task process occupying 100% CPU. Upon googling and looking for help on different forums, including following some advice and moving system files around to no avail, I finally dug up the system diagnostic disc and run a test. Lo and behold, it found that the left side cooling fan has died. Once this came to light now everything made perfect sense. Since one fan has stopped working, the computer was trying to avoid overheating itself by running the other working fan at high speed, to try to draw heat away, while the CPU was throttled down by this kernel_task process. No amount of moving around system files were going to resolve it until I got that fan replaced.

So the bottom line is, a proper diagnostic is needed in order to find out the root cause. Granted in some cases a software problem could have been fixed by reinstalling the OS, but if the problem is hardware, it can only be addressed by removing/fixing the offending piece of equipment.

This solved the issue in my MacBook Pro 13" early 2011 Snow Leopard 10.6.8

fantasticbobski said:

Okay, I seem to have solved the kernel_task PCU drain using this method I stumbled across on the web.

1. Go to About this mac under the apple in the upper left and click on More info
2. Click on system report
3. make a note of what it says after Model Identifier
4. go to your master drive – System -Library – Extensions – IOPlatformPluginFamily.kext -Contents – Plugins – ACPI_SMC_PlatformPlugin.kext – Contents – Resources – find the name from step 3 and move it to a folder that you can find again if needed.
3. Restart and you’re done
I hope this helps.

Only problem now is the battery won't register, new or old and the fan is running 100% of the time.

Click to expand...

My MacBook Pro were showing issues with the battery. A day the battery was OK, the next day it showed a cross with "No batteries available". After several months of he battery issue, a day I let the laptop ON all the night, the next day was impossible to use it, CPU peaking at 300% on kernel_task, after several restarts, shutdowns I googled this matter and applied the before mentioned solution. It solved the issue.

EasyGoing1 said:

I'd just like to comment on these KINDS of comments ... in general (i'm not picking on you specifically schmidtl)...


I know there are a lot of you guys out there who squeeked through high school with straight A's .... no friends .... and even graduated a virgin ... and I know you get all excited when you think you can help people by boldly pontificating your vast and infinite computer wisdom in these forums ... but let me tell you that for every one of you, there are probably thousands of us shaking our heads knowing that your fishing for ego boost and we just sit quietly by - not saying anything in the interest of professional courtesy...

But honestly ... the next time you're tempted to be the hall monitor of self assist problem solving ... do all of us a favor and just keep scrolling ...

Mike

Click to expand...

Oh, you were doing so well oh great and wise master, right up until this bit.

What a ridiculously petulant and arrogant thing to say, especially hilarious given that your original point was about how much people "like to hear themselves talk" and that they're "fishing for an ego boost".

Methinks the lady doth protest too much.

Any more nuggets of golden wisdom mined out with your bare hands after years of experience?

Do I have to prove I'm not a virgin before I can give advice on the forum? Or do I have to prove I wasn't a nerdy kid with good grades in school first?

Pray tell, fearless and wise leader, what must I do to please you?

My simple solution

I had the same problem: sudden dramatic lag in performance, kernel task CPU usage going past 150%. I spent the last frustrating 48 hours trying the various kext/SMC reset/battery test angles, none of which worked. Then I thought maybe it had something to do with overheating. I opened up my 13" MBP and yeah, found clogging dust buildup in and around the vents. I blew it all out with canned air and oh sweet relief: kernel issues vanished, everything working smoothly again! Please give this a try...

I have the same problem. My MBA 2014 model has the screen damaged. I tried to removed the screen and connect it with an old 15" LCD (1024x768) via mini display port.

After I have opened the back cover and unplug the original screen. Kernel task existed. Over 80% cpu usage comes with rapid fan speed.

I have reset pram, smc, reinstall osx, rebuilt kext cashe, startup from safe mode, etrecheck it, delete model identifier, or even downgraded to maverick. Still couldn't solve it.

Is it possible for the panic to exist if the original screen wire harness of the motherboard left unplugged?

Please help!

Chip