How to solve kernel_task high CPU usage?

Discussion in 'MacBook Pro' started by fantasticbobski, Feb 14, 2014.

  1. blago macrumors newbie

    Aug 3, 2016
    there is no 12,1 identifier on the list
  2. joeInShmoe macrumors newbie

    Oct 2, 2016
    if your are familiar with the system level files, you will know that in order to solve a problem like this involving "kernel_task", that you have to mess around with the system files. and since this person had already reinstalled the system, the worst he would have to do is ... reinstall the system... so he did the right thing, he did research, and then tried it. and his research turned out to be very good.

    what he did was the correct thing to do, which was to remove a system level plist file that is regenerated by the system.
    and most of all, solves the problem of "kernel_task" taking over the CPU processing cycles so nothing else can get done.

    and if someone notices the "kernel_task" going haywire, I highly recommend doing this, and it will not harm your system, because it is just a plist file....

    the problem one may run into is following those directions, one has to know how to open a package that you are at, with a right click, to go see the "content" folder... so they will have to have some knowledge to get to the file to delete it.

    (oh and his battery problem, and high fan speed is/was some other problem)
  3. sroot macrumors newbie

    Nov 24, 2012
    PLEASE DON'T DO THIS unless you know what you are doing or can afford the risk of breaking your machine permanently. I looked at the file and realised it contains settings designed to protect the device from overheating (amongst other things I'm guessing). Perhaps removing the file from the system will use some other defaults but the settings in this file have been set specifically based upon the hardware you bought. No settings or other settings could be very bad. That explains why your fan went to 100%... but mine wouldn't have...

    So, I didn't delete this file and the next day I realised my laptop was unusually quiet, especially for a high CPU situation that was making work almost impossible. Then I realised the fan wasn't running, and remembered this suggestion and the contents of the file.... and realised the problem wasn't software, it was a fan failure.
    The laptop will run without the fan but as the processor overheats it throttles back to prevent heat damage, which I noticed as poor performance and a High CPU usage of kernel_task .

    I was able to temporarily fix my fan (removed cover, vacuumed away the dust) and for now things are back to normal.
  4. Stanick macrumors regular


    Aug 30, 2014
    Sofia, Bulgaria
    Sorry for bumping this old thread but I'm doing it for someone like me who used this thread by looking for solution in google to the high kernel_task CPU usage fix.

    Actually, although this "ACPI_SMC_PlatformPlugin.kext" fix "works" to reduce the CPU usage, it also reduces performance of the machine. At least for my MacBook air. I had a high CPU usage by kernel_task due to a faulty internal microphone. Every time I went to YouTube kernel_task was skyrocketing and playing videos was choppy. So I searched google and found this "fix". Initially I was really amazed. The kernel_task process was magically fixed and YouTube was back to normal. I noticed a decrease in overall responsiveness of the OS but didn't really paid much attention until I decided to do a Geekbench test and compared to a Geekbench I took prior to applying the fix. The score was 50% lower. Tested 5 times. Then I undid the "fix" and Geekbench increased by 50% in both single core and multi-core. I disable my internal mic and now everything is back to normal, no high CPU by kernel_task and back to normal performance... My point is, this fix will not work wonders for everyone...
  5. MacEns macrumors newbie

    Nov 4, 2016

    It appears that OS X or macOS uses other model identifiers for certain Macs if you cannot find your own identifier. This appears to be the case for me as well with my iMac13_2. This can be remedied by deleting all of the files.

    It's probably a good idea to copy the folder and place it somewhere else before deleting it entirely.
  6. qsch1 macrumors newbie

    Apr 30, 2013
    I have tried moving the files which you said would work and also tried the terminal command, unfortunately it will not let me move files as indicated it is system files and I am not permitted, same with terminal. Any ideas, maybe do not have enough priveleges. Surprising as I am the admin.
  7. dlmcilvain macrumors newbie

    Dec 6, 2016
    WOW! Can I say that again? WOW! This totally helped me. My Kernel_task was running between 270-225% CPU and slowed everything down. I am now around 2 to 5% and back to where I should be. Thanks for posting!!!
  8. Blazer1120, Jan 3, 2017
    Last edited: Jan 3, 2017

    Blazer1120 macrumors newbie

    Jan 3, 2017
    --- Post Merged, Jan 3, 2017 ---
    I had the very same problem, high CPU usage. My problem happened to be as originally stated by one poster to this thread, a device issue. I noticed that the touchpad was a bit askew and the click was not responsive. I opened the bottom cover, removed the battery, to discover that the battery was swollen and causing the touchpad to activate. I replaced the battery with one from another system. Now, both the battery charge issue and the processor issue have cleared up. Sytem is now functioning properly. If you are using an aftermarket battery, check it to see if it is indeed swollen and creating a touchpad issue.
  9. Christoffee, Jan 8, 2017
    Last edited: Jan 14, 2017

    Christoffee macrumors regular


    Jul 26, 2012
    Like many people here I tried many things on my early-2011 MBP (8,2) before resorting to this, but this is an instant fix. So far, no adverse consequences - battery registers and fans are silent.

    I heed all the warnings, and I shall keep a close eye on CPU usage and the ability of the computer to apply the fans at the right time. It's a 6 year old computer, so to get another couple of years out of it will be a bonus. So if I blow it up it's not the end of the world. Hopefully it will last until USB-C is better supported and Apple get their MacBook act together.

    Many thanks.

    EDIT: As others have said, performance is down massively. When encoding videos and audio the CPU works at maximum (according to iStat) but the CPU doesn't get warm, let alone hot, and the process takes much longer. Anecdotally probably 3 times as long. Good news is, my fans will last much longer!
  10. hjschr, Jan 16, 2017
    Last edited: Jan 23, 2017

    hjschr macrumors newbie


    Jan 16, 2017
    Vero Beach, Florida
    Hmm, I got a MacBook Pro 10,1 and I can't find any plist file reflecting that name. I am almost tempted to try removing the 1_1 plist file, but thought asking here first of what to do... THANKS!

    Did some more experiments. UPDATE: my problem has been caused by two things: a) dirt in the air passways in the Macbook, and b) missing screws fastening the back side of the lower cover to the frame structure of the machine. It seems that the cover needs a thermally tight connection to function as a heat dissipator. The computer works now as expected.
  11. snakethumper macrumors newbie

    Jan 23, 2017

    I solved it this way:

    just leave the machine on, plugged into power, for at least 2 to 3 days

    the background task, whatever it is, finally finishes and goes away - but it takes days

    I found this out because this particular MBP that i use is a "backup" for my main MBP (which i use live on stage with Apple Mainstage). So i only fire it up to copy files and dont leave it on for very long, hence the problem.

    Hope this helps
  12. gwestcott macrumors newbie

    Jan 3, 2010
    YOU TOTALLY SAVED ME!!! I have had this problem ever since I used an external battery.
    Maybe because I am running Yosemite I could only find this file:
    But once I removed it and restarted my computer, I don't have the problem anymore. My CPU isn't all red and full anymore.

    Thank you so much.
  13. marielosp macrumors newbie


    Feb 25, 2016
    I solved my CPU lag problem. I bought a new MacBook Pro 2016 and sold the old one. All my Photoshop, Cintiq Companion Hybrid performance issues, Skype screen share lag, inability to use photoshop and run video at the same time without Photoshop becoming unusable, all of those issues solved. And the silence... fantastic. (My previous was MacBook Pro 15 Retina, mid 2012, 16 gb RAM, 500gb SSD, 1GB VRAM)
  14. dude-mate macrumors newbie

    Feb 15, 2017
    --- Post Merged, Feb 15, 2017 ---
    I discovered that the kernel task using high CPU is due to a faulty device. In my case, kernel task was using 121% (not sure how applemac got that figure) and went down to 3.3% when I replaced the internal battery. So moving the file that was mentioned in previous posts is not fixing the cause but might stop the mac from checking I/O integrity which also results in lower overhead on CPU. However, as Blazer1120 also found the battery to be the cause, I would recommend starting with a new battery as the first step.
  15. Gustavo Gomes macrumors newbie

    Feb 21, 2017

    Ok so I followed all the steps but when I was at the end of step 4 and I went into the resources file there was no iMac14,1. What do I do??
  16. sonoma141 macrumors newbie

    Feb 23, 2017
    --- Post Merged, Feb 23, 2017 ---
    What is to be done with file from step 3, once found and moved? Was able to get to this file and saved a copy on desktop.
  17. cookies!, Apr 11, 2017
    Last edited: Apr 11, 2017

    cookies! macrumors 6502

    Jul 3, 2011
    I hope this helps—my issue was resolved, at least temporarily, by forcing my fans to spin at max RPM using iStat Menu. This instantly and reproducibly stopped the high CPU usage in its tracks. I'm wondering if the high CPU usage is related to the system throttling the CPU due to high heat?

    However: 1) the sensors are not showing that the laptop is hot (it's at 60C), 2) the laptop is well ventilated, 3) all fans are spinning fine and automatically adjust their speeds when I transcode or do something else CPU-intensive, and 4) this only happens sometimes and at random, regardless of CPU load.

    SMC resets didn't help, so I'm thinking there is a faulty sensor or something that is causing this issue for a lot of people. It might be a widespread manufacturing defect in that case. But my 2014 MBP is out of warranty, so I guess I'll never know :p

    My battery has also been displaying strange behavior as of late too—I'm only getting 2-3 hours of moderate use, and I used to get around 6. All utilities and checks show the battery has ~90% health, ~300 cycles. It's the original Apple battery. I'm wondering if this has something to do with it since someone mentioned their battery swelling in this thread.
  18. rikfilho macrumors newbie

    Apr 17, 2017
    Thank you! In my case was an old HDMI cable that was messing up with the kernel_task, just replaced it and the kernel_task is now with 11% CPU usage instead of 500%!
  19. Adrie macrumors newbie

    Apr 20, 2017
    Thank you this helped me a lot. I had to start up from an external disk in order to remove the file though.
    --- Post Merged, Apr 20, 2017 ---
    Thank you this helped me a lot. I had to start up from an external disk in order to remove the file though. No problems with the fan.
  20. nutty4gymn macrumors newbie

    Apr 24, 2017
    So I am not understanding step #4? Can you clarify as it seems to include multiple paths? Thanks!
  21. Skika macrumors 68030

    Mar 11, 2009
    So how much % of kernel task usage is normal in idle or light usage(safari,itunes)
  22. CatBoxHero macrumors newbie


    Apr 30, 2017
    Portland, OR
    Just wanted to chime in and say I had the same kernel_task problem after replacing the screen assembly on a 2014 MacBook Air. All the various resets didn't help. I opened it up again and disconnected the camera cable. Poof. No more high CPU usage by kernel_task. My hypothesis is that there are slight variations in camera hardware out there and the driver was hanging. I suspect a re-install of the OS would have cleared it up by detecting and installing the correct driver. I just left it disconnected, since we don't ever use the camera on this machine anyway.
  23. nutty4gymn macrumors newbie

    Apr 24, 2017
    So I upgraded to 16GB RAM and poof problem solved. Also learned from another page that the later OS versions do not run well on 4GB RAM which is what I had. A memory upgrade is the answer I guess.
  24. Jim breese macrumors newbie

    May 13, 2017
    --- Post Merged, May 13, 2017 ---
    I have a 2010 MacBook Pro that has two weird symptoms:

    It runs 10.6.3 well, but when I load 10.6.8, it slows to a crawl and the kernel task usage goes to about 170%

    The fan runs full speed all the time

    In order to find out what might be causing these two difficulties, I have reviewed about 20 sites on the Web, and I have read a lot of stories and suggestions and tech tips and other stuff. The results of my investigation are listed below, so others with the same problem will not have to repeat all this research. All these suggestions seemed to me to be worth consideration for one reason or another. You get to make your own decisions about what to try, of course…

    1. Do SMC reset and PRAM reset

    2. Create a new user account, and log in with that account, just to see if that changes the symptoms

    3. Use SAFE startup

    4. Clear caches and temp files

    5. Run Disk Utility—First Aid

    6. Remove the battery, run off the charger

    7. Remove the battery and replace it with a new Apple battery

    8. Use the iStat menu to control the fan

    9. See if the temperature sensor is working—you can load SMCFanControl to do this; it’s free

    10. Turn off HDMI and other interfaces

    11. Tilt the computer various ways to see if the problem might be related to a poor connection somewhere.

    12. Remove the logic board and clean it, and replace the board. Examine all the cables carefully while doing this

    13. Do the “rdoxenham” fix, which involves moving a kext file out of its normal home

    14. Run “etrecheck” to examine hardware

    15. Run Apple Hardware Test (AHT) or Apple Diagnostics (AD)

    16. Move “sysstat” stuff out of the way and re-boot

    17. Check to make sure the fan actually runs

    18. Change the cable to the hard drive

    19. Turn OFF Sharing in System Preferences

    20. Delete PC Share

    21. Look for a faulty internal microphone; try disabling it

    22. Leave the computer on for a day or more, to give it time to finish “indexing”

    23. Disconnect the camera cable

    24. Upgrade to 8GB memory

    25. In Console, look for loaded kext files that are not Apple-branded

    26. Remove all the login items, then re-start

    27. Find the “reportCrash.self” file and copy it to Launch Items
  25. lvntclkl macrumors newbie

    May 26, 2017
    What if there is no model identifier .mine is 13.1 there is 12.2plist
    --- Post Merged, May 26, 2017 ---

    l ve same problem but model modifier of mine is 13.1
    problem is there is no 13.1.plist there is anyone helps me?

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