If you run processor-intensive apps frequently, it is a good idea to keep an eye on your Mac’s CPU usage. Fortunately, Apple makes it easy to get a quick look at CPU usage and CPU history by changing the Activity Monitor dock icon. Here̵
CONNECTED: Troubleshoot Your Mac Using Activity Monitor
First, open “Activity Monitor”. If you don’t know how, Spotlight makes it easy. Click the little magnifying glass icon in your menu bar (or press Command + Spacebar). When the Spotlight Search bar appears, type in “Activity Monitor” and click “Return”.
When the Activity Monitor opens, you can close the main window with the red “X” button as you don’t need it. (If you want to get it back later, choose Window> Activity Monitor from the menu bar or press Command + 1.)
Then right-click on the Activity Monitor icon in the Dock. A menu will appear. Select “Dock Icon” from the menu and you will see several options. First select “Show CPU usage”.
If “Show CPU usage” is activated, the dock icon of the activity monitor changes to a 10-segment display that lights up depending on the CPU activity. For example, if all 10 segments are lit, you are using 100% of your CPU capacity.
If you right-click the Activity Monitor dock icon again and choose Dock Icon> View CPU History instead, you’ll see a black rectangle showing CPU usage over time. The display flows slowly from right to left, with periods of heavy CPU usage adding height to each column. The red squares represent the CPU usage by system processes and the green squares represent the CPU usage by user processes.
To change the Activity Monitor icon back to normal, right-click the Dock icon again and select Dock Icon> Show Application Icon. Alternatively, you can configure the Activity Monitor dock icon via the menu bar in the “View” menu. Select the Dock Icon option and you’ll see a menu similar to the one you used earlier.
When you’ve configured the dock icon the way you want it, just leave the activity monitor running in the background while you perform other tasks. The display of CPU usage or CPU history in the Dock is constantly updated over time and you can let the display run indefinitely. However, the Activity Monitor must still be running for it to work. Once you close the app, the dock icon will go back to normal. Just like Cinderella’s pumpkin!