Those are passive solutions. You'd be looking at them after you realize something doesn't look right. iStat or similar can do a notification if a process is ta

Those are passive solutions. You'd be looking at them after you realize something doesn't look right. iStat or similar can do a notification if a process is taking high CPU usage for a while. Servers have their own solutions like monitoring daemons that sends out an alert if CPU usage had been too high for a while.