It's never fun when your computer is running slowly, but it's worse when you can't figure out why it's so slow. If you've shut down all the programs you can and everything on your Mac still feels like it's moving through molasses, this could be a sign of the dreaded kernel_task causes high CPU usage.
On your Mac, kernel_task is the name for a variety of low-level functions that allow the rest of your computer to work. This means that it can be difficult to find the culprit.
We have seen this many times, so we have a handful of tips to help you solve this problem.
Diagnosing a slow Mac
If your Mac appears to be running slowly, generates a lot of heat, or sounds like it's about to take off due to high fan speeds, then you should open it up Activity monitor and find out why. This is essentially the macOS equivalent of the Windows Task Manager.
You can open the Activity Monitor with Spotlight: just press Command + Space Then start typing "Activity" and it should come up. You can also find under Applications> Utilities, and you may want to pin it to your dock for quicker access if you have major problems.
The reason for your slow computer should be because of the Central processor Tab. Just click % CENTRAL PROCESSOR Column heading to organize running processes according to processor load. Everything that needs a lot of computing power is shown above. they move around while your computer does various things in the background.
In general, high CPU usage is only an issue when you aren't expecting it. It is reasonable to expect your computer to consume resources when you play a game, watch a video in your browser, or edit a video. Generally, when a single Safari tab or Mac process is using more than its fair share, it means something went wrong.
Why is kernel_task the culprit?
You can end most processes by clicking on them and then clicking X in the upper left corner of the screen. Unfortunately, this is not possible for a specific process: kernel_task. The reason for this is that kernel_task is actually part of macOS.
It is not so much a single process as it is actually a series of processes under one label. While you work, macOS does all sorts of tasks in the background. This includes sending and receiving data over the network, writing and reading data to the hard drive, and indexing new folders or hard drives for Spotlight searching.
This process will often use up a lot of your available RAM on the memory Tab, but that's a lot less worrying. The amount of memory used will increase and decrease as needed. However, high CPU usage can bring your entire system to a standstill and even lead to the occasional complete system crash.
So how can you keep the kernel_task from affecting your Mac's performance?
Simple solutions to kernel_task problems
In many cases, simply restarting your Mac will fix the problem immediately. However, this isn't a permanent, long-term solution if you've had this problem for a long time. It is only a short term solution that should produce immediate results.
Whatever is causing the substantial increase in CPU usage can come back. So if you've had repeated incidents, you should try resetting your System Management Controller (SMC) as well. It's easy and can fix a wide variety of macOS issues.
The instructions on how to reset the SMC will vary slightly depending on what model of Mac you have. Since it can fix so many problems, we have a complete guide on how to reset your Mac's SMC. It also covers resetting your PRAM, another part of a Mac that can cause multiple problems.
Other solutions to fix kernel_task high CPU usage
Perhaps the most obvious solution to operating system-related issues is to update to the latest version of macOS. Just start System settings, click Software updateand run any pending Apple software updates.
Another common cause of high CPU usage by the kernel_task process is Adobe Flash. Long gone are the days when Flash was essential for surfing the web, but you still may need it for a specific web application or website.
Instead of leaving Flash installed, you can use a browser like Google Chrome that provides Flash (albeit optional). Most likely, you don't need Flash at all, so it can be safely removed. Also, as Adobe stopped supporting Flash on December 31, 2020, you will not receive any critical security updates.
It's important that you remove it – at least for security reasons. To remove Flash, run the Adobe Flash Player installation manager and click Uninstall.
Dive a little deeper into the Mac's high kernel_task CPU usage
Some people have had success removing kernel extensions, which are modules of code capable of performing low-level tasks. Also known as "kexts", the vast majority of these extensions are installed by Apple as part of the macOS core environment. Some software installs third-party extensions as drivers or to control hardware.
A quick way to see if a third-party kext is causing your kernel_task problems is to restart your computer in safe mode. To do this, restart your computer and hold the shift Key as it boots. Safe mode only loads the necessary kernel extensions. So, if the problem doesn't occur in this environment, it indicates a problem with a third-party kext.
To dive into it, restart your system as usual and start up terminal. Then run the following command:
This indicates which kernel extensions are currently loaded. All Apple extensions look like this:
In the meantime, third-party drivers include the developer name as follows:
And also like this one:
The best way to remove these is to uninstall the associated software. For some apps, this simply means moving the application file to the trash and then entering your admin password to allow the change.
Others may have a PKG uninstallation file that you need to run. For the rest, go to System settings and look for third-party preference panels.
Starting with OS X El Capitan, Apple introduced a new security feature that broke through a number of third-party modifications. System Integrity Protection, or SIP for short, prevents apps from injecting code into Apple's own apps and writing it to certain parts of the drive that Apple considers important for system security.
This leads to better system stability, so this problem should be less common in modern versions of macOS.
Are you still experiencing high CPU usage? What to do when all else fails
The final solution here is a bit risky: removing Apple's own kernel extensions. This is not recommended. However, if you've tried everything else and the Kernel_task is still causing high CPU usage, this is a solution you might want to try.
Developer and blogger Viktor Petersson has written extensively about kernel_task and the problems it poses. In his case, it was likely caused by a dodgy sound card. Petersson's first post focused on Mac OS X Yosemite, but later followed suit with updates for later versions of macOS.
We haven't tested this update and we can't tell if it will work for you. If you want to try it out, here's what you need to do:
Back up your Mac using Time Machine or another backup solution.
Disable System Integrity Protection by booting into recovery mode and running the following command from the terminal:
Follow Viktor's method. Start by finding your Mac model with the following command:
system_profiler -detailLevel mini | grep "model identifier:"
Run the following command:
Move and save the file relevant to your model. For example, if your ID is. is MacBookPro8,2 you would run:
sudo mv MacBookPro8_2.plist MacBookPro8_2.bak
Reboot into recovery mode and re-enable System Integrity Protection with the command:
This is also a last resort. Only try if you're having trouble getting something done because kernel_task is rendering your Mac unusable. This is not a short-term solution – it will persist even after you reinstall your operating system.
Even so, you'll need to repeat this process after every major software update or operating system upgrade, as Apple will restore the moved file.
Fixed the Mac kernel_task bug problem
In general, upgrading to a new version of macOS brings new features and capabilities, but it can also introduce bugs. This is especially true for older hardware models that are starting to push the limits.
However, if you don't see issues with kernel_task on your Mac until after an update, this could be the culprit. Hopefully one of these tricks helped you fix the problem and improve your Mac's performance.
10 easy ways to tweak your Mac for the best performance
Instead of seeing how long it takes without breaking a dreaded New Year's resolution, use the start of the year to freshen up your Mac.
About the author
(120 published articles)
Kris Wouk is a musician, writer and whatever it is called when someone is making videos for the web. He's been a tech enthusiast for as long as he can remember, has definitely favorite operating systems and devices, but still uses as many others as possible to keep up-to-date.
By Kris Wouk
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