Non-Algorithmic Load Imbalance Effects for Domain Decomposition Methods on a Hypercube

In this paper we discuss the effects of non-algorithmic load imbalance for three synchronization structures which appear in different algorithms using domain decomposition methods for solving PDE's on a hypercube machine. The synchronization structures are determined from the conditions related to the partitioning of a hypercube. To characterize the load imbalance effects we introduce a factor 'V defined as the ratio of the load imbalance costs to the total parallel execution time in absence of any load imbalance. We develop non-deterministic models for SPMD (Same Program Multiple Data) execution model and compute the 'V factor for the three structures, for different types of distributions of the execution time.