Which utility would you use to monitor CPU usage of individual processes updated every three seconds?

The most suitable utility for monitoring CPU usage of individual processes, updated every three seconds, is top.

Top is a widely used command-line tool that provides a real-time view of system processes and their resource consumption. One of its key features is its ability to refresh the display at a configurable interval, with the default being every three seconds. This real-time monitoring is crucial for system administrators and users who need to evaluate the performance and resource usage of running applications promptly.

While htop also provides a similar function with a more user-friendly interface that allows users to view CPU and memory usage of processes, it may not be set to update specifically every three seconds by default. Instead, users can customize its refresh rate, but it is not the primary designed function compared to top.

The ps command is static and provides a snapshot of currently running processes without continuous updates, making it less suitable for real-time monitoring. vmstat focuses more on overall system performance statistics related to virtual memory, processes, and CPU activity, rather than individual process monitoring.

Therefore, top is the most appropriate choice for monitoring CPU usage of individual processes with the desired update frequency.