So my MacBook Pro is getting super slow and laggy after a while of usage. I updated to Sierra today and my kernel_task is sky-rocketing - hitting up to 1100% and I have no idea why? I've tried all kinds of things like an SMC and PRAM reset and it didn't work. Has anyone had the same issue? Does anyone have a fix?

Edit: I have 8GB of RAM and a 250GB SSD with 35GB of free space.

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  • There are many possible reasons for this. Can you please share how much RAM you have and what capacity HDD you have and how much free space remains?
    – Monomeeth
    Sep 23, 2016 at 21:42
  • i have 8gb of ram and a 250gb ssd with 35gb free space Sep 23, 2016 at 21:46

1 Answer 1


So after long time of surfing the web i found this which fixed the issue:

  1. Reboot into recovery mode (Command + R on boot prior to startup chime), select Utilities/Terminal, csrutil disable (repeat process, use csrutil enable after removing the file), reboot.

  2. Go to About this mac under the apple in the upper left and click on More info

  3. Click on system report

  4. make a note of what it says after Model Identifier (MacBookPro8,2 is mine).

  5. From the Root drive (not home folder): – System Library – Extensions – IOPlatformPluginFamily.kext (alt-click/View Contents) – Plugins – ACPI_SMC_PlatformPlugin.kext – View Contents – Resources -– find the name from step 3 and move it to a folder that you can find again if needed.

  6. Restart and you’re done (other than enabling SIP).

I can use my Mac again!

  • The recovery menu is broken on Sierra, it's stuck on Language Chooser. You can user Command + R + S instead. May 28, 2017 at 0:54

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