Monitoring CPU performance

Displaying system processor activity

mpstat - multiprocessor statistics
mpstat will display the percentage of kernel and user code running and the percentage of idle time. It will also indicate whether each CPU is active or inactive.

cpuonoff -c
Displays CPU status, either active or inactive.

uptime displays the system load average:
load average is the average number of processes in the kernel’s run queue at any one instance.
Therefore the higher this figure is the more loaded the system.
i.e. load average: 11.73, 11.01, 10.18 - This shows the load average over the last minute, the last five minutes and the last fifteen minutes.
The figures reported here are very high and therefore the system is over loaded.
It can also been seen that the load average is climbing so is getting worse.