Activity Monitor – Why Search is Disabled

There is a bug in Activity Monitor v10.8.0 (806). If you select Dock Icon > Show CPU History, is automatically closes the floating window and appears in the dock. If you attempt to switch back to the floating window, sometimes only one core appears.

Solution: - Close floating windows - Dock Icon > Show Memory Usage - Quit and Restart Activity Monitor - Dock Icon > Show Application Icon - Quit and Restart Activity Monitor - Monitors > Show CPU History

Now you should see all of your cores/vccores. :-)

This bug is not always reproducible, but I've experienced it before.

Check this out for a previous post. But, adding a bit to that answer...

First - while you have 4 physical cores, you have hyperthreading active, which allows each core to serve as 2 virtual cores. This will give you a theoretical maximum CPU usage of 100% x 8, or 800%.

Second - the % reported in the activity monitor is showing total CPU% (so it won't exceed 100%). Looking at the CPU numbers in your table, you're using a bit more than 485% out of the maximum of 800%. 485/800 is about 60%, which is your total usage reflected here...