Has your Mac's performance gone downhill fast? If you're no longer enjoying the snappiness you've come to expect from your Apple computer, it could be because your system resources are being swallowed up by bad or buggy software. A simple way to identify potentially problematic apps is to keep an eye on CPU usage.
In this guide, we'll show you how to find out what's taking up CPU power at any time using the Activity Monitor built into macOS. We'll also look at how to identify the most power-hungry applications, and how you can more effectively manage system resources so that you don't run into frequent slowdowns.
What is a CPU?
In a nutshell, your Mac's CPU is essentially the brain of the machine. It's made up of billions of transistors, and it processes and executes all instructions, working closely with your system's RAM, GPU, and other components to keep everything ticking over nicely. Your CPU plays a key role in determining how performant your Mac is overall.
Although it's just one of many important parts inside your computer, the CPU is what ties everything together. It does a great job of this until your software throws too much at it and the CPU becomes overwhelmed. This is when you'll start to experience slowdowns, freezes, and even complete computer crashes. By managing CPU power more effectively, you can help ensure everything else runs more smoothly.
How to monitor CPU usage on Mac
Your first step when your Mac isn't performing as expected is to check CPU usage. You can do this within Activity Monitor by following these steps:
- Open the Applications folder on your Mac, then open the Utilities folder.
- Double-click Activity Monitor to run it.
- Click the CPU tab at the top of the screen if it isn't already selected.
- Click the % CPU column header to sort all processes by CPU usage.
The CPU load indicator at the bottom of Activity Monitor shows you how much CPU power is being used at a glance. However, you can get a more accurate picture of this by keeping an eye on the figures in the % CPU column. These tell you which apps are putting your CPU to work, and how much power they're claiming.
To monitor real-time CPU usage while you're working, there's a neat trick to turn the Activity Monitor icon in your Mac's dock into a CPU usage monitor:
- While Activity Monitor is running, right-click its icon in the dock.
- Select Dock Icon > Show CPU Usage.
Managing CPU power more effectively
Once you know which apps are hogging processing power, you can start taking steps toward improving the performance of your Mac. The first should be to identify any software that's showing excessive CPU usage. It's normal for apps to require a lot of resources while they're carrying out intensive tasks, but you shouldn't see heavy CPU usage from apps that are idle.
When this happens, it may be that the app isn't running as intended — perhaps because of a bug that needs fixing. When you're not using the app, keep it closed (not just hidden or minimized) so that it can't call for CPU power. When you do need to use it, or any other intensive application, close other software you don't need, so that your CPU isn't trying to keep up with instructions from countless apps simultaneously.
It's also a good idea to manage background processes. Much of the software we use today may perform tasks even when we haven't consciously opened them, all of which eat into processing power. In Activity Monitor, look for apps that you haven't opened and ensure they aren't set to run in the background. Also, check your Login Items and remove any apps that you don't want to run automatically when your Mac boots up, like this:
- Open System Settings on your Mac.
- Click General > Login Items.
- Select any apps you don't want to run at startup, then click the minus (-) button.
Final thoughts on checking Mac CPU usage
Modern computers rely on a lot more than just CPU power, but the CPU remains the core component of any Mac. Managing its resources and ensuring that they're used effectively helps everything else operate more efficiently. Regularly monitoring CPU usage in Activity Monitor will help you identify the biggest causes of CPU slowdown, as well as potentially problematic apps that may need to be killed.