How to Monitor Activity on an iMacby K.C. Winslow
An iMac runs the Mac OS X operating system. Included in the operating system is a utility called Activity Monitor. This utility allows you to view all of the active processes on the iMac. It also displays the disk activity, CPU usage and system memory usage. The Activity Monitor helps you to understand the effect of various applications and processes on the performance of an iMac.
Open the "Applications" folder and double-click on the "Utilities" folder. Double-click on the "Activity Monitor" icon.
View the active processes in the top portion of the window. Navigate between the tabs along the bottom to view the CPU, system memory, disk activity, disk usage and network usage.
View a specific activity category in the Dock as a replacement for the Activity Monitor icon by pressing the "Option" key and clicking on the Dock icon. Select "Dock Icon" and choose one of the options. A live, updated icon shows the activity selected as long as the Activity Monitor is open.