I like to keep on top of my machines health. I like to do this without programs getting in my way, or dedicating desktop space to monitoring applications. The way I’ve found to do this simply and effectively is with the System Monitor panel Applet.
Adding the System Monitor Applet
To add the system monitor applet to one of your panels (I prefer the top panel), simply right-click and select “Add to Panel”. Scroll down until you see “System Monitor: A system load indicator”. Select it and select Add. You should now have a small black box on your panel which will monitor cpu activity.