Try watching the CPU Load at the bottom of the Activity Monitor window and the percentage used by System, User, and Idle. On my Mac mini (3.2 GHz, 6 Core, i7) with the percent
idle at 96.4%. The high CPU using tasks are
- Devonspherebot 98.4%,
- Window server at 24.4%,
- kernel task at 10.4% and
- Activity Monitor at 6.7%.
If my processor cores are idle well over 90% of the time why would I be concerned about a task, Devonspherebot, that is using 98% of the CPU cycles that are being used is the point I am trying to make.
Activity Monitor has evolved as MacOS has matured. We used to focus on swap file activity to indicate whether or not more memory was needed until Apple changed the memory management algorithms and we switched to the "MEMORY PRESSURE" graph at the bottom of the Activity Monitor "Memory" window as the more accurate representation of memory usage. I am not sure when Activity Monitor changed how to judge CPU usage, but from what I am seeing in Catalina, the most accurate place to begin, like memory, is the "CPU LOAD" graph at the bottom of the CPU Window.
