How to Fix kernel_task High CPU Usage on Mac: 9 Best Ways

Is your Mac acting like it’s stuck in molasses? When your Mac starts to slow down or become unresponsive, a culprit often consumes your system’s resources. One of the most notorious offenders is the kernel_task process, which can hog a significant amount of CPU usage, affecting your Mac’s overall performance.

So, if kernel_task consumes excessive CPU resources, I’ve got a guide covering quick to advanced solutions to fix kernel_task high CPU usage on Mac. Dive in for proven solutions like restarts and SMC resets to get your system back on track.

What Is kernel_task on Mac?

Kernel_task on a Mac is a core part of macOS, responsible for managing system resources such as CPU, memory, and disk access. It serves as a bridge between the hardware and software, ensuring all operations occur smoothly and efficiently.

In a sense, kernel_task acts like a traffic cop, allocating resources where needed most. For example, it regulates CPU temperature by managing its workload and prioritizes tasks to ensure optimal system performance.

However, if kernel_task consistently uses a high percentage of your CPU, it may signal issues such as outdated software or insufficient ventilation, slowing down your system.

What are the Causes of kernel_task High CPU Usage?

High CPU usage by kernel_task on a Mac can occur for various reasons, and pinpointing the exact cause may require troubleshooting. However, common triggers for kernel_task high CPU usage on Mac include the following:

1. 🔥 Overheating: If your Mac gets too hot, kernel_task may consume more CPU to throttle down system performance, aiming to reduce heat generation.
2. 🕰️ Outdated Software: Running an older version of macOS or outdated drivers can lead to high CPU usage issues.
3. 🛠️ Hardware Problems: Faulty RAM, hard drive issues, or other hardware malfunctions can cause kernel_task to act up.
4. 🖥️ Resource-Heavy Applications: Some apps are notorious for consuming a lot of system resources, which could lead to elevated CPU usage by kernel_task.
5. 🔄 Background Processes: Software updates, scheduled tasks, and background services can sometimes consume significant resources.
6. 💽 Insufficient Disk Space: A lack of free disk space can sometimes trigger high CPU consumption as the system struggles to perform basic tasks.
7. 🗂️ Corrupted System Files: Sometimes, corrupted or missing system files can disrupt normal operation and increase CPU usage.
8. 🔌 Peripheral Devices: Occasionally, connected external hardware like printers, USB drives, or other peripherals can cause issues with kernel_task.
9. 🌐 Network Issues: Unstable or slow internet connection on Mac can also lead to elevated CPU usage.
10. 🦠 Malware or Viruses: Although rare on Macs, malicious software can also cause abnormal CPU usage, including by the kernel_task.

How to Check CPU Usage on Mac

Before diving into the nitty-gritty of solving performance issues like high CPU usage, it’s crucial to know how to monitor CPU activity on your Mac. Knowing which processes are consuming your system resources can provide invaluable insights into what might be slowing down your computer.

Here’s how to check the CPU usage on your Mac:

1. Navigate to Applications > Utilities > Activity Monitor, or use Spotlight Search (Command ⌘ + Space) and type Activity Monitor.

2. Once Activity Monitor is open, click the CPU tab to see a list of processes along with their CPU usage.

3. You can click the % CPU column to sort processes based on CPU usage. High percentages indicate higher usage.

How to Fix kernel_task High CPU Usage on Mac

Performance issues on a Mac can be overwhelming, especially when confronted with high CPU usage from kernel_task. While essential for system stability, this enigmatic process can sometimes turn into a resource hog, grinding your Mac’s performance to a halt.

The good news is you’re not powerless against it. Armed with the right strategies, you can take control and optimize your system’s performance by fixing kernel_task high CPU usage on Mac.

1. Switch the USB Charging Port

If you’re charging your MacBook through a USB port, especially if you’re also using additional peripherals or dongles, the system can sometimes get confused and engage kernel_task to handle what it perceives as a resource conflict or an overheating issue.

Simply unplug your charger from its current USB port and plug it into a different one. If you’re using a USB hub or dock, consider connecting the charger directly to your Mac’s native port. It may reset the internal controls, causing kernel_task to hog your CPU, improving system performance.

2. Prevent Your Mac From Overheating

Overheating is not just detrimental to your machine’s performance, it can also have long-term implications on its lifespan. It’s crucial to address this issue head-on to alleviate immediate performance woes and ensure the ongoing health of your Mac.

Below, I’ve shared a few tips to prevent your Mac from overheating and avoid kernel_task high CPU usage on Mac.

a. Move to a Cooler Space

Sometimes, the simplest solutions are the most effective. If your Mac is situated in a hot or poorly ventilated area, it can easily lead to overheating and high CPU usage by kernel_task. The fix could be as straightforward as moving your computer to a cooler, more ventilated space.

Whether relocating to an air-conditioned room or simply moving your laptop from a cushioned surface to a hard table that allows better airflow, the change in environment can significantly impact your Mac’s internal temperature. 

b. Use a Cooling Pad

Investing in accessories like cooling pads and laptop stands can go a long way in preventing your Mac from overheating and, in turn, reducing high CPU usage by kernel_task.

Cooling pads are designed with built-in fans that enhance airflow around your Mac, making it easier for the system to regulate its temperature. Place your MacBook on a cooling pad or an ergonomic stand aimed at elevating the device for better airflow. It will improve airflow and prevent overheating.

c. Clean Your Mac

Dust and debris inside your Mac can obstruct airflow and contribute to overheating, leading to high CPU usage by kernel_task. Cleaning your Mac could provide a quick and tangible improvement in its thermal performance, reducing the need for kernel_task to hog your CPU as a cooling measure.

To clean your Mac, you can use a soft microfiber cloth or a can of compressed air to blow out dust from the vents, ports, and fans. It’s crucial to do this carefully to avoid damaging internal components.

d. Close Resource-Intensive Apps and Programs

Running multiple resource-intensive applications or programs can push your Mac’s hardware to its limits, causing it to overheat. This prompts kernel_task to consume a significant portion of your CPU to manage the system load.

Closing these heavy-duty apps can free up system resources, reduce heat generation, and alleviate the need for kernel_task to step in as a mitigating force. Here’s how to use Activity Monitor to close programs with high CPU usage:

1. Open Activity Monitor from your Applications folder.

2. Click the CPU tab to view each application’s percentage of CPU usage.

3. Identify any applications using excessive CPU resources and quit or close them by selecting the program and clicking the small x icon in the top bar.

Alternatively, you can use MacKeeper’s Memory Cleaner to clear memory and make Mac’s performance better. Here’s how:

1. Download and install MacKeeper. 
2. Launch MacKeeper and click Memory Cleaner. 

3. Click Open in the memory cleaner.

4. Select the Apps & Processes tab and click the x next to an app consuming excessive system resources to close it.

5. Confirm by clicking Quit in the prompt window. 

e. Use Safari Instead of Chrome

Google Chrome is notorious for its high CPU and RAM usage on Mac, which can contribute to overheating and trigger elevated kernel_task activity. Switching to Safari could make a difference if your Mac is running hot and kernel_task is consuming a lot of CPU.

Here’s how to switch to Safari:

1. Click the Apple menu and select System Settings.

2. Click Desktop & Dock in the left sidebar.

3. Scroll down and look for the Default web browser option.

4. Click the pop-up menu next to Default web browser and select Safari from the list of available browsers.

5. This will set Safari as your default browser on Mac, and any links you click will open in Safari by default.

f. Adjust Your Mac’s Graphics Settings

If you often run graphics-intensive applications or games, your Mac’s GPU can generate a lot of heat, potentially leading to high CPU usage by kernel_task. Adjusting your Mac’s graphics settings can help mitigate this problem by reducing the workload on your GPU and the heat it generates.

Here’s how to adjust your Mac’s graphics settings:

1. Click the Apple icon and select System Settings.

2. Select Displays.

3. Choose a lower resolution to reduce graphics usage.

4. Your Mac will require less processing power for resolution and not overheat.

3. Restart Your Mac

When all else fails, sometimes a simple restart is all it takes to resolve many issues, including high CPU usage by kernel_task. Rebooting your Mac clears temporary files, ends stuck processes, and frees up system resources, offering your computer a fresh start.

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.

4. Uninstall Unused Apps

Over time, your Mac can become a repository for rarely used apps and programs. While they may seem harmless sitting in your Applications folder, some of these apps may be running background processes, consuming system resources, and contributing to high CPU usage by kernel_task.

Uninstalling unused or unnecessary apps can free up valuable CPU and RAM, improving system performance and potentially reducing the burden on kernel_task. 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.

Alternatively, you can use MacKeeper to uninstall unwanted apps on your Mac:

1. Download and install MacKeeper on your Mac.
2. After installation, launch MacKeeper and click the Smart Uninstaller in the left-hand menu.

3. Click Start Scan.

4. Select the applications you want to delete from the list and click Remove Selected.

5. Tap the Remove button on the pop-up to confirm the deletion.

6. MacKeeper will uninstall the apps and remove associated files and folders. You will get a Removal Completed notification. If you want to scan your Mac again, click Rescan.

5. Reset Your Mac’s SMC

The System Management Controller (SMC) is a subsystem on Intel-based Macs that controls low-level functions like power management, system performance, and hardware-related issues.

Sometimes, a corrupted or malfunctioning SMC could lead to problems like high CPU usage by kernel_task. Resetting the SMC can often fix such issues and help your Mac run more smoothly.

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.

6. Boot Your Mac into Safe Mode

Booting your Mac into Safe Mode can serve as a diagnostic tool when facing issues like high CPU usage by kernel_task. Safe Mode limits the number of processes and drivers that start with your system, making it easier to identify if a particular software or driver is causing the issue.

Here’s how to boot your Mac in Safe Mode:

a. Apple Silicon Macs

1. Click the Apple icon and choose Shut Down from the drop-down menu.

2. Wait for your Mac to shut down completely, and press the Power button to turn it on.

3. Keep holding the Power button until you see the Loading startup options screen.

4. Select a volume from the options.

5. Press and hold the Shift ⇧ key and click Continue in Safe Mode.

6. Your Mac will restart automatically, and you will see Safe Boot in the menu bar when the login screen appears.

b. Intel-Based Macs

1. Restart or turn on your Mac and press and hold the Shift ⇧ key immediately.

2. Keep holding the Shift ⇧ key until you see the login screen.
3. Release the Shift ⇧ key and log in to your Mac.
4. You may be asked to log in again.
5. You’ll see Safe Boot in the menu bar on your first or second login window.

After your Mac starts up, check the CPU usage to see if kernel_task is still consuming a high percentage. If it’s normal, you can restart your Mac to exit Safe Mode and start identifying which software or drivers might be causing the issue when running in regular mode.

7. Reset the NVRAM/PRAM on Your Mac

NVRAM (Non-Volatile Random-Access Memory) and PRAM (Parameter RAM) are small memory spaces your Mac uses to store certain settings and access them quickly. These settings include display resolution, time zone, and startup disk preferences.

Occasionally, corrupt or incorrect NVRAM/PRAM settings can lead to issues like high CPU usage by kernel_task. Resetting this memory can be a quick way to resolve such problems.

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. Scan Your Mac for Malware

Malicious software, or malware, can wreak havoc on your Mac in various ways, including causing high CPU usage by kernel_task. Some malware programs are designed to consume your system’s resources, perform tasks in the background, or disrupt normal operations.

So, scanning your Mac for malware can be essential in resolving issues related to excessive CPU consumption. 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.

9. Update Your macOS

Software updates often come with bug fixes and performance improvements that could resolve issues like high CPU usage by kernel_task. Apple regularly releases updates to address various system inefficiencies and vulnerabilities, so it’s a good idea always to install the latest version available.

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.

Bring Your Mac’s High CPU Usage Down

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

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

• Like kernel_task high CPU usage, you may experience WindowServer Mac high CPU usage due to outdated OS, too many background processes, third-party app conflicts, and graphics card issue.
• You should kill unnecessary background processes on your Mac to ensure they don’t interfere with your system.
• LaunchDaemons can be exploited for malicious purposes, so you must catch and remove hidden LaunchDaemons on Mac to protect it from malware.

Frequently Asked Questions