vtop
A graphical activity monitor for the command line
...We calculate the CPU percentage as a total of your overall system power. 100% is all cores and HyperThreads maxed out. This is different to how Apple Activity monitor works. If your terminal supports mouse events (like iTerm) then you can click on the items in the process list. As well as use the scroll wheel. You can disable mouse control with the vtop, no-mouse option.