5 ways to reduce Mac CPU usage

5 min read

High CPU usage on your Mac could be the reason your device has become painfully slow. 

If you're constantly waiting for applications to load or find yourself gazing at the spinning beachball more than you'd like, it's time to check your CPU usage and jump into troubleshooting mode.

What is CPU usage on Mac?

CPU (Central Processing Unit) is essentially responsible for performing all of your system tasks; often referred to as the brain of a Mac, it executes commands and instructions and interacts with all other parts of your Mac.

Although CPU usage constantly changes, depending on which activities your Mac is running, high usage can cause multiple issues for Macs, including:

  • Decreased system performance.

  • Overheating.

  • Crashing, freezing, or stalling applications.

If you've noticed your device is suffering from any of the issues above, jump to the next step, and I'll show you how to check the CPU usage on your Mac.

How much CPU is normal for macOS? 

Surprisingly to many Mac users, there is no recommended percentage of CPU usage. But obviously, the higher the usage, the slower your Mac performance will become. If the CPU usage is edging around 100%, your Mac is trying to do more work than it has the capacity for.

Luckily, it's easy to reduce Mac CPU usage and speed up your Mac; let's go.

How to check CPU usage on Mac

Thanks to Apple's built-in Mac performance monitor, Activity Monitor, it's simple to check your CPU usage; here's how:

Activity monitor

  1. Select Finder > Applications > Utlitiles > Activity Monitor.

  2. Select the CPU tab from the top and sort by CPU.

Here in Activity Monitor, you'll see precisely what applications and programs are running and what resources they are using. The highest CPU-consuming tasks will be located at the top of the list.

Notice the graph at the bottom; this shows a breakdown of your CPU consumption. To end any CPU-hungry tasks, simply select it from the list and press the "X."

How to reduce CPU usage

1. Update your Mac

Keeping your Mac up-to-date is the surest way to resolve multiple issues, including high CPU usage on Mac. 

If your Mac is slow, a quick system update can work wonders; here's how:

How to update Mac

  1. Select the main Apple menu > About This Mac. 

  2. Here, click Software Update.

If, like me, your Mac has an update available, follow the on-screen instructions to install it.

2. Remove unnecessary login items

Launch agents and login items can bombard your system upon startup, using vital resources and increasing CPU usage.

You can significantly improve your system performance by removing unnecessary items from automatically launching when your Mac starts up.

I like to use the Apple notarized tool CleanMyMac X to help me manage the job; its Optimization Module makes it easy to remove unneeded launch agents, close hung applications, and heavy consumers all in one go; here's how:

CleanMyMac X - Launch Agents

  1. Launch the app — download the free version here.

  2. Select Optimization from the sidebar and press View All Tasks.

  3. From login items, select which items are not needed and press Remove. Repeat for launch agents.

  4. If you have any hung applications or heavy consumers, they will be listed; simply follow the on-screen instructions to manage these.

Third-party apps are not for everyone, so if you'd rather manage these manually, follow these steps.

Users & groups settings

  1. Select the Apple menu > System Preferences > Users & Groups.

  2. Press the lock icon, bottom left to make changes.

  3. From the list, select your user profile and press Login Items.

  4. Select the applications you wish to remove and press the "-" button.

3. Reset your SMC

SMC stands for System Management Controller; it gives power to your Mac's keyboard, battery, fan, and other critical device hardware. If one or more of these items stop working correctly, the kernel_task process could ramp up your CPU load. Resetting your SMC can resolve this issue and give your Mac some breathing room; here's how:

M1 Macs

Although you can't reset the SMC on M1 Macs as the new M1 chips manage all functions, many users report that shutting down your Mac completely, waiting 30 seconds then restarting acts something like an SMC reset— worth a try.

Desktop Macs 

  • Remove the power cord and wait for 15 seconds before plugging it back in.

  • Wait for a further 5 seconds and turn your Mac on.

Laptops with T2 chip

  • Turn off your Mac, then press and hold the following keys for 10 seconds: Control-Option-Shift-Power button

  • Now, hold the following keys for 7 seconds: Control-Option-Shift

  • Now add the power button and hold for 7 seconds.

  • Release all keys, then turn on your Mac.

Laptops with non-removable batteries

How to reset SMC

  • Once your Mac is turned off, unplug the power cord.

  • On the left side of the keyboard, press and hold the following keys:

Shift-Option-Control-Power button

  • Hold down for ten seconds, then release.

  • Plug your Mac back on and switch it on.

Laptops with removable batteries

How to reset SMC

  • Turn your Mac off, remove the power adapter and battery.

  • Hold down the power button for five seconds, then release.

  • Put the battery back in, connect the adapter and turn your Mac on.

4. Free up RAM

Another way to speed up performance and improve high CPU usage on your Mac is by freeing up your RAM, giving your Mac extra room to breathe.

You could waste considerable time trying to do this manually by removing browser extensions, deleting old apps, system logs, and temporary files, or you could use the app I mentioned earlier.

CleanMyMac X has a handy Maintenance module that can free RAM and run maintenance scripts quickly; here's how:

  1. Open the application and select Maintenance from the sidebar.

  2. Press View, All Tasks, then select Free Up RAM and Run Maintenance Scripts from the list.

  3. Press Run.

5. Declutter your Desktop

As a last tip, take a few minutes to clean up your Desktop. Unnecessary clutter not only slows down your Mac but can consume resources.

Move unwanted items to the Trash, remembering to empty it afterward.

Now you know how to reduce high CPU usage on your Mac.

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