High CPU usage on Mac OSX

A question, if I may, so I can compare with a few Macs I have access to. Does the 50-60% CPU usage you mention mean 50-60% of a single core is used, or 50-60% of the whole CPU? In case of my MacBook Pro it’s the former, so the whole CPU is 90% idle (see screenshot), but maybe in your case it’s the latter?