Time—The Zeroth Performance Metric

Abstract

Time is the basis of all computer performance management (Fig. 3.1). It is so fundamental that it could be called the zeroth-order performance metric. In the context of computer performance analysis, time manifests itself in a multitude of metrics like service time, response time, round-trip time, memory latency, and mean time to failure, to name just a few. In view of this variety, it would seem fitting to open a book on performance analysis with a review of these various performance metrics. Surprisingly, there seems to be no precedent for such a discussion in any of the readily available textbooks on computer performance analysis. It is about time someone provided a brief discourse about time, and that is what we offer in this chapter.