Solved: How do I fix Kernel_task causing high CPU usage on MacBook?

Problem Symptom

This article outlines the detail steps to fix MacBook lag and slow even after closing all the running apps, which mostly causing by kernel_task process automatically activated when startup the operates in the background by default.

The main function of the kernel_task is to return the MacBook processor’s temperature to a normal range but it is a very resource-intensive operation. The problem happens if MacBook’s CPU is overtaxed and unable to get back under control.

Follow the below solution steps to resolve the kernel_task problem and get MacBook back to normal.

Potential Causes

• Connecting to an external monitor.
• Infected by virus or malware.
• MacBook’s fan isn’t operating properly.
• Outdated Zoom app.
• Corrupted configuration in Zoom app.

Pre-check

Before you proceed to kick start the troubleshooting steps below, make sure you have close all the unnecessary apps and restart your macOS.

Solution 1: Disconnect external monitor

Step 1: Disconnect the external monitor.

Step 2: Shut down the macOS.

Step 3: Connect Mac to a power source through the MagSafe power adapter.

Step 4: Press the Power button and the Shift + Control + Option combination keys together on the built-in keyboard.

Step 5: Release all keys and the Power button at the same time to reset the SMC.

Step 6: Press the Power button to turn on the Mac.

Step 7: Shut down the macOS again.

Step 8: Press and hold the Command + Option + P + R combination keys shortly after the starting sound.

Step 9: If the computer does not restart after hearing the starting sound a second time, press and hold these keys for several seconds to perform the NVRAM reset.

Step 10: Log in macOS as per normal.

Step 11: Reconnect the external monitors. Continue to monitor the CPU and memory usage of kernel_task using Activity Monitor application.

Step 12: Open the Activity Monitor application from the Applications Utilities menu.

Step 13: Locate the kernel_task in the Process Name column.

Step 14: Look up for the CPU %.

Step 15: Navigate to the Memory tab to check how much RAM is being used.

Solution 2: Scan MacBook using antivirus software

Malware may take up all the Mac’s processing power, causing the CPU and memory to operate at close to 100% capacity. Run a complete disk scan on the MacBook with antivirus program in order to identify and eliminates malware fast and effectively, avoiding viruses and malware from wasting MacBook resources.

Solution 3: Reset SMC (System Management Controller)

The MacBook’s keyboard, fan, battery, and other components are powered by the System Management Controller (SMC) powered. If MacBook’s fan isn’t operating properly, the kernel_task process may cause high CPU load. Perform below steps to reset the SMC.

For MacBook Air and MacBook Pro 2018 or equipped with the T2 security chip

Step 1: Shut down the macOS.

Step 2: Unplug the power adapter from MacBook.

Step 3: Press the Shift + Control + Options combination keys on the keyboard for seven seconds.

Step 4: Press and hold the Power button without releasing the three keys.

Step 5: Release all four keys together after ten seconds.

Step 6: Press the same keys (Shift + Control + Options + Power) again at the same time.

Step 7: Press the Power button once more to start the macOS.

For MacBook released in 2017 or before

Step 1: Shut down the macOS.

Step 2: Unplug the power adapter from MacBook.

Step 3: Press and hold the Shift + Control + Options combination keys on the keyboard for seven seconds.

Step 4: Press and hold the Power button without releasing the three keys for another five seconds.

Step 5: Press the Power button once more to start the macOS.

Solution 4: Reset NVRAM (non-volatile random-access memory)

Step 1: Shut down the macOS.

Step 2: Press the Power button once to start the macOS.

Step 3: Hold down the P + R + Option + Command combination keys immediately after the display comes up or when you hear the starting sound.

Step 4: Keep holding those four keys until the MacBook restarts.

Solution 5: Start macOS in safe mode to diagnose

Step 1: Press the Power button and wait for the MacBook to shut down completely.

Step 2: Press the Power button then instantly press and hold the Shift key.

Step 3: Release the Shift key when the Apple logo displays on the screen.

Solution 6: Update Zoom app

Step 1: Start the Zoom app.

Step 2: Sign in the Zoom app.

Step 3: Click on the profile picture located at the top right corner.

Step 4: Select the Check for Updates option. The Zoom app update will start automatically.

Solution 7: Change Zoom app settings

Step 1: Start the Zoom app.

Step 2: Sign in the Zoom app.

Step 3: Click on the profile picture located at the top right corner.

Step 4: Select the Setting option.

Step 5: Click on the Video option in the sidebar.

Step 6: Make sure the Original ratio option is checked. Uncheck the HD option, Mirror my video option, and Touch up my appearance option.

Step 7: During the Zoom meeting carry on, use the Speaker View instead of Gallery View.

Step 8: Change the Maximum participants displayed per screen in Gallery View to 25 participants.

Step 9: Click on the Share Screen option in the sidebar.

Step 10: Click on the Advanced link.

Step 11: Check the Limit your screen share to 10 frames-per-second option and set the value of frames-per-second to 4.

Solution 8: Re-install Zoom app

Step 1: Start the Zoom app.

Step 2: Click on the zoom.us in the menu bar located at the top of the screen.

Step 3: Select the Uninstall Zoom option.

Step 4: Click on the OK button to proceed to uninstall Zoom app.

Step 5: Proceed to download the latest Zoom Client installer from the official Zoom Download Center.

Kernel task Macbook high CPU