How to Fix kernel_task High CPU Usage on Mac: 8 Best Ways

Having used a Mac for years, I rarely face problems, but high CPU usage is one issue that gets under my skin. When the kernel_task process recently caused this slowdown, I had to figure out a fast fix. Here are some simple fixes that worked perfectly for me.

What Is kernel_task on Mac?

kernel_task is a process on your Mac that helps manage your system’s resources, like CPU, memory, and temperature. Think of it as a traffic controller, making sure everything runs smoothly by balancing tasks and preventing the CPU from overheating.

If your Mac gets too hot, kernel_task can slow down the CPU to cool it off. While it’s essential for system stability, sometimes it can use too much CPU, which may slow down your Mac.

How to Fix kernel_task High CPU Usage on Mac

Here, I have shared to fix the kernel_task high CPU usage on Mac:

1. Restart Your Mac

Restarting your Mac is a quick way to clear temporary files and processes, which can resolve high CPU usage by kernel_task. Here’s how to restart your Mac:

1. Click the Apple logo located in the upper-left corner of your screen.
2. From the dropdown menu, choose Restart.

3. Click Restart on the pop-up window.

2. Prevent Your Mac From Overheating

Keeping your Mac cool helps reduce kernel_task usage and improves speed. Below, I’ve shared a few tips to prevent your Mac from overheating:

1. Close Heavy Apps: Running too many apps or programs can strain your Mac and cause overheating. Close unused apps, especially resource-heavy ones like games or video editors.
2. Move to a Cooler Space: Place your Mac in a cooler, well-ventilated area and avoid using it on soft surfaces like beds that block airflow.
3. Clean Your Mac: Dust can block your Mac’s vents and fans, causing overheating. Regularly clean them with a soft cloth or compressed air to keep airflow smooth.

3. Uninstall Unused Apps

Removing unused apps frees up resources, reducing the load on kernel_task and improving overall system efficiency. Here’s how to uninstall apps on your Mac:

1. Click the Launchpad icon in the Dock, or use the Mac keyboard shortcut key: F4.

2. Scroll through the apps in Launchpad until you find the app you want to uninstall.

3. Click and hold the app icon until it starts shaking, and an X icon appears on the top-left corner of the app icon. Click the X icon to delete the app.

4. Tap the Delete button on the confirmation dialog box to move the app to the Bin in the Dock.

5. After deleting the app, right-click the Bin icon in the Dock and select Empty Bin.

4. Update Your macOS

Updating macOS ensures you have the latest bug fixes and improvements, which can help fix high kernel_task CPU usage. Here’s how to update your macOS:

1. Back up important files and data before proceeding with the update.
2. Go to the Apple menu and select System Settings.

3. Click General and select Software Update.

4. If an update is available, you’ll see its details. 
5. Click Update Now to initiate the update process.

6. Follow the prompts to complete the update. Your Mac may restart one or more times during this process.
7. After your Mac restarts and the update is installed, open Finder to see if the issue has been resolved.

5. Scan Your Mac for Malware

Scanning for malware helps detect hidden programs that may be consuming system resources and causing high kernel_task usage. Here’s how to run a virus scan on your Mac using MacKeeper Antivirus:

1. Download and install MacKeeper.
2. Launch MacKeeper and navigate to the Antivirus tab in the left sidebar.

3. Initiate an instant virus scan by clicking the Start Scan button.

4. If any viruses are detected during the scan, click the Fix Items button to resolve the issues.
5. If your system is threat-free, you’ll see a No threats found message. You can tap the Restart button to run the scan again.

6. Enable real-time antivirus protection to safeguard your Mac from future threats by clicking the Enable button.

Once you have configured your security settings, MacKeeper will continue to operate in the background, diligently scanning for threats and actively blocking any malicious activity.

6. Reset Your Mac’s SMC

Resetting the SMC can resolve system management issues, including problems that lead to high CPU usage by kernel_task. Here’s how to reset the SMC on your Mac:

a. With a Removable Battery

1. Shut down your Mac. 

2. Remove your MacBook’s battery.

3. Press and hold the Power button for 5 seconds while the battery is removed.

4. Release the Power button and reinstall the battery.

5. Turn on your Mac by pressing the Power button.

b. With Non-Removable Battery

1. Tap the Apple icon and select Shut Down from the drop-down menu.

2. Press and hold the Shift ⇧ + Control ^ + Option ⌥ keys with the power button for 10 seconds.

3. Release all the keys and press the power button to turn on your MacBook.

7. Reset the NVRAM/PRAM on Your Mac

Resetting NVRAM/PRAM can fix corrupted settings that may be causing kernel_task to use too much CPU. Here’s how to reset the NVRAM/PRAM on your Mac:

a. On Intel-Based Macs

1. Turn off your Mac.
2. Press the power button to turn on your Mac.

3. Press and hold the Option ⌥ + Command ⌘ + P + R keys simultaneously on your Mac’s keyboard before the gray screen appears.

4. Keep holding the keys until your Mac restarts and you hear the startup chime twice. If you have a Mac with the T2 Security Chip, keep holding the keys until the Apple logo appears and disappears twice.
5. Release the keys and let your Mac start up normally.

b. On Apple Silicon Macs

On Apple Silicon Macs like the M1 and M2, you don’t need to manually reset the NVRAM as you would on older Intel-based Macs. These newer models automatically check and reset the NVRAM as needed during the startup process.

There are no special key combinations to hold down, simply shutting down your Mac and powering it back on will prompt the system to perform necessary NVRAM resets automatically.

8. Boot Your Mac into Safe Mode

Booting your Mac into Safe Mode helps diagnose high CPU usage by reducing the number of apps and drivers that run. Safe Mode also checks your disk and disables some features, making it easier to spot any issues. Once in Safe Mode, check if kernel_task CPU usage goes down.

For detailed steps on how to boot your Mac into Safe Mode, check out this guide.

Bring Your Mac’s High CPU Usage Down

The strategies I’ve outlined offer a comprehensive approach to diagnosing and fixing the kernel_task high CPU usage on Mac, from switching USB ports to keeping your macOS updated.

If you want to keep your Mac in top shape, here are a few more tips for you:

• WindowServer high CPU usage can result from an outdated OS, background processes, app conflicts, or graphics issues.
• Kill unnecessary background processes to avoid system interference.
• Remove hidden LaunchDaemons to protect your Mac from malware.

Frequently Asked Questions