What is performance in the context of computer systems and why is it so difficult to define?

Question

What will be an ideal response?

Answer 1

Performance is not easy to define. Typical dictionary definitions are vague; for example, “a thing done or carried through”, or “the accomplishment of a given task measured against preset known standards of accuracy, completeness, cost, and speed.” However, most would agree that performance tells us something about how well a task is executed. In the world of computing, performance is an indication of the speed of a computer. We can either measure the time taken to execute one or more tasks, or the rate at which tasks are performed.

However, measuring the speed of a computer is difficult because it depends on so many factors. When we measure the performance of athletes, they are expected to run a given distance and their time is measured. A computer’s performance depends on the CPU, its cache memory, the buses, the memory, and so on. What exactly are we measuring? It’s really like measuring the performance of an athlete by timing them from the moment they get up, get dressed, eat breakfast and then get to the stadium. The actual race gets lost in all these other details. Moreover, the performance of a computer may vary depending on the task it is performing.