Why CPU stats between ps and top Command are Different

The difference between CPU statistics from ps and top is:

• ps calculates CPU utilization as total CPU time divided by the task’s running time.
• top displays a percentage of overall CPU time.

With the ps calculation, a process that has run for a long time but used little CPU will show the following when we run: #ps -up PID Its CPU utilization (%CPU) is very low. To see current CPU utilization, use top, which is more accurate for that purpose than ps.