Global analysis with HPMCOUNT

HPMCOUNT investigates the performance of an entire application. However, several of the rates listed among the derived metrics make use of the wall-clock time. A typical run used for the performance analysis of an application contains very sizable overheads. The initialisation of the application and the exchange of initial and final data with the mass storage are examples for the sources of these overheads. Such overheads can distort the results for these rates considerably when comparing short test jobs to proper production run. Despite these limitations, we feel HPMCOUNT is a very useful tool, particularly since it is so simple to use.