Performance Modelling of Grid Problems - A Case Study on the SUPRENUM System

Abstract The suitability of a simple performance modelling approach based on workload analysis is shown for hierarchical bus-coupled systems like SUPRENUM. The kernel of a red-black SOR method for solving the Poisson equation in 2 dimensions is selected as test example. First a model for the considered application and machine is developed. Time cost functions for the primitives of this machine model containing performance and size parameters of the configuration are determined. A model representing the relations between the parallel processes is evolved to combine the time cost functions of the components. Using this model, the runtime of the abstract application is estimated. The performance parameters are determined by measurements on the SUPRENUM system. Experiments on the real machine have shown that a good accuracy can be achieved. Modelling has also shown in which way the performance of small problems running on large systems is reduced by the SUPRENUM bus.