Q: Problem with Kernel Task - El Capitan

The kernel is using excessive processor cycles. Below are some possible causes for the condition.

Throttling

When it gets high temperature readings from the hardware, or low voltage readings from the battery of a MacBook, the kernel may try to compensate by interrupting the processor(s) to slow them down and reduce power consumption. This condition can be due to:

☞ a buildup of dust on the logic board

☞ high ambient temperature

☞ a worn-out or faulty battery in a portable

☞ the malfunction of a cooling fan, a temperature sensor, a voltage sensor, or some other internal component

Note that if the problem is caused by a sensor, there may be no actual overheating or undervoltage.

If the computer is portable, test with and without the AC adapter connected. If kernel_task hogs the processor only on AC power, charging is causing the machine to heat up. That behavior may be normal for some models, but it may also be an indication of a hardware fault.

Apple Diagnostics or the Apple Hardware Test, though not very reliable, is sometimes able to detect a fault. For more thorough hardware testing, make a "Genius" appointment at an Apple Store, or go to another authorized service provider.

If nothing is wrong with the hardware, then whatever you can do to improve cooling may help.

Installed software

User-installed software that includes a device driver or other kernel code may thrash the kernel. That category includes virtualization software, such as Parallels and VMware, as well as most commercial "anti-virus" products. Some system-monitoring applications, such as "iStat," can also contribute to the problem. You can test for this possibility by completely disabling or removing the software according to the developer's instructions, or starting in safe mode. Note, however, that disabling a system modification without removing it or testing in safe mode may not be as easy as you think.

Corrupt NVRAM or SMC data

Sometimes the problem is cleared up by resetting the NVRAM or the SMC.

External display

Connecting an external display to some MacBook Pro models while the lid is open may cause this issue. If applicable, use the external display in clamshell mode.

Thanks Linc Davis! This is really helpful. Assuming the kernel_task issue is due to a software installation, what is the fix for it?

Any additional help would be much appreciated, and thank you!

TL;DR

I can't just do without the likely software culprits such as vmware (I've also been suspicious of R and LaTeX). My kernel_task is currently running 1.34GB of RAM at 136 threads (and no change over the course of writing this post).

As for the other possibilities, this happens to my MBPro (and the MBAir before it) regardless of external display connectivity, regardless of the fact that I have reset the NVRAM & SMC controller on numerous occasions with no improvement, and temperature isn't an issue due to good environment. I should note that this often happens when I come back to the computer after it's been sleeping for some indistinguishable period of time. When I acquired the MBPro, I set it up from scratch without using Migration Assistant.

It is an hardware problem?

Yes. The logic board is faulty.

Thank you, Linc Davis.

I have had recurring kernel_task problems in Yosemite and now El Capitan, always associated with the connection of external devices (ext. display, ext. audio).

Clamshell mode seems to have fixed it for now.

Again, many thanks.

Tim W.

I had this issue with a previous upgrade and this fix worked great. However, in El Cap this is a protected system file.  In order to delete it you need to:

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

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 (MacBookPro8,2 is mine).

4. 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.

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

I can use my Mac again!

Late 2011 15", i7 2.2, 16GB 1333, 1TB hybrid drive, OSX 10.11.1

I'm doing something wrong. I copy the file macbookpro8_2.plist to a folder, restart, and still having problems. Kernel task still using over 500%. Wth!?!?

I just dragged it to my desktop, then to my Things folder after moving it from it's original location to the Trash.  What's your device and OS?  When did it start?  Is anything else it's doing weird or wrong?

No, it's not.  It could be, but telling people that as an absolute could cost people a lot of money unnecessarily.  Hardware malfunction after a software update would be more likely to be coincidence.

I Have a macbook pro 15 early 2011. 2Ghz core i7. 4gb ram. computer is very slow. track pad cursor is jumpy. Slow to respond to any commands. Bought the computer used recently. Running os 10.11.

Open Activity Monitor, select View all processes - What's using most of your CPU?

Kernel task

Malacaih,

I've had kernel_task issues with several different OS versions - Mountain Lion, Yosemite and now El Capitan.

For me, kernel_task most frequently misbehaves when my MacBook Pro 8,2 is connected to external devices - an external monitor, something plugged into the audio out (headphone jack), etc.

Try using the computer standalone - starting the computer with all external devices disconnected - and see if that resolves kernel_task swallowing up all your CPU cycles.  If so, connect one external device, reboot, launch Activity Monitor and observe. Disconnect, shut down, and connect a different (and only one) external device, and lather, rinse, repeat.  Essentially, try to identify which external device is pulling the trigger on kernel_task.  Depending on what you observe, there may be specific (or more global) solutions available to you. 

Hope this helps some.