If you frequently use applications that use a lot of your processor power , it's a good idea to keep an eye on your Mac 's CPU usage . And luckily for you, Apple makes it easy to quickly and easily check your CPU usage and history by changing the Activity Monitor Dock icon.
First, to set it up, open “ Activity Monitor .” If you don’t know how, Spotlight makes it easy. Click the little “magnifying glass” icon in the menu bar (or press Command + Space ). When the “ Spotlight Search ” bar appears , type “Activity Monitor” and press “ Return .”
Once Activity Monitor opens, you can close the main window, as you won't need it anymore. If you want to open it again later, go to Window > Activity Monitor in the menu bar or press Command + 1.
Then, right-click on the Activity Monitor icon and a menu will appear. In the menu, select “Dock Icon” and you will see several options. For now, select “Show CPU Usage”.
With “Show CPU Usage” enabled, the Activity Monitor icon will turn into 10 segments that light up, depending on CPU activity. For example, if all 10 segments are lit, 100% of your CPU capacity is being used.
If you right-click the Activity Monitor icon and choose Dock Icon > Show CPU History, you'll see a black rectangle that tracks CPU usage over time. The screen flows slowly from right to left, with periods of heavy CPU usage being the tallest in each column. The red squares represent CPU usage by system processes, and the green squares represent CPU usage by user processes.
If you want to change the icon back to normal, right-click the “Dock” icon again and select Dock Icon > Show Application Icon. Alternatively, you can also configure the Activity Monitor Dock icon from the menu bar. Select “Dock Icon” and you will see a menu similar to the one you were using earlier. Once you have configured the Dock icon the way you want, simply leave Activity Monitor running in the background as you perform other tasks. The CPU or CPU History display in the dock will continue to update over time. However, for this to work, Activity Monitor must remain running.
