Hierarchical Performance Modeling With MACS: A Case Study Of The Convex C-240

The MACS performance model introduced here can be applied to a Machine and Application of interest, the Compiler-generated workload, and the Scheduling of the workload by the compiler. The Ma, MAC, and MACS bounds each fix the named subset of M, A, C, and S while freeing the bound from the constraints imposed by the others. A/X performance measurement is used to measure access-only and execute-only code performance. Such hierarchical performance modeling exposes the gaps between the various bounds, the A/X measurements, and the actual performance, thereby focusing performance optimization at the appropriate levels in a systematic and goal-directed manner. A simple, but detailed, case study of the Convex C-240 vector mini-supercomputer illustrates the method.