Timing results in the table represent the data set with 8192 hexahedrons, implicit computation and flux computation by the Sanders-Prendergast scheme. The number of Iterations is 287, the total computation time 3557s. In a first step the compiler optimization possibilities were investigated and the best settings were determined, e.g. optimization level 4, no IEEE and vectorization switched on for all but 2 modules. Successful code changes were performed in the module eparpi. Through a split of the compute intensive loops the cache reuse was enhanced.
Synchronization is one of the major reasons for low performance of parallel algorithms.
Characteristic feature of asynchronous parallel algorithms is that they contain no blocking receive operations, but try to incorporate data of other processes not before it is really available. The applicability of this strategy becomes clear by observing that variations in interactions between particles over time, from which the dynamic of the system eventually results, are of different time scale , depending on e.g. the particles' distance and the nature of the interaction. Amody considers potentials resulting from particle pair-interactions where xk denotes the position of particle k in the simulation domain. This bound stands in good relation to those of other strategies. Additionally, actual errors in simulations turned out to be much smaller.