Late Breaking: Measuring Processor Utilization in Windows and Windows Applications

Introduction. This paper discusses the legacy technique for measuring processor utilization in Windows that is based on sampling. This technique for measuring processor utilization is efficient and generally adequate for capacity planning. However, it lacks the precision performance engineers require for application optimization and tuning, particularly over small measurement intervals. The paper then introduces newer techniques for measuring processor utilization in Windows that are event-driven. The eventdriven approaches are distinguished by far greater accuracy, enabling the reconstruction of the precise path that threads, processes and processors take when they execute. Gathering event-driven measurements entails significantly higher overhead, but measurements indicate this overhead is well within acceptable bounds on today’s high powered server machines.