Display Processor Usage in the Dock
I rarely use 3rd party applications when an alternative in already available bundled with the operating system. Launch the Activity Monitor application located in the directory /Applications/Utilities, which is most easily obtained by launching Spotlight (press and hold the command key directly to the left of the spacebar while simultaneously depressing the spacebar) and type in the words Activity Monitor, then press the enter key once you’ve highlighted the program.
Once the application is launched, right click on the application icon in the Dock, go to Options and select Keep in Dock. Right click on the dock icon again, select Dock Icon and Show CPU Usage.
From this menu you can monitor CPU history, network usage, disk activity or memory directly in the dock.