Good performance is crucial to many applications. Program performance tuning is a multifaceted activity which is grounded in measurement and analysis. Measurement provides an objective basis for assessment and comparison of approaches.

AMD Athlon™ 64 and AMD Opteron™ processors have extensive features for performance measurement. These features use hardware counters to measure the occurrence of performance-related events as user- or kernel-level software executes. Event counts help a systems engineer or software developer to identify the likely cause for a performance issue.

The purpose of this technical note is to describe a collection of basic measurements which can be taken using the performance measurement features of AMD Athlon 64 and AMD Opteron processors. Sections 2 recommends a few online resources about the AMD Athlon 64 and AMD Opteron microarchitecture, performance events that can be measured, and the tools to use to measure them. Section 3 provides background information about one of the measurement techniques known as "event counter sampling." Section 4 presents the basic performance measurements at a glance with the full details given about each measurement in Section 6. The use of a few common measurements is illustrated in Section 5.