Conditions for Scalability of Mesh-connected Massively Parallel Processors

Several metrics are used when comparing processing elements of different massively parallel processors. The most common being computational performance (flops/second), memory capacity (bytes) and communication performance (bytes/second). We show that for an important class of problems, namely three-dimensional simulation in real space performed on mesh-connected massively parallel processors, it is the relationship between the metrics, rather than their individual values, that determine scalability. We show that processing elements with different metrics can result in the same scalability behavior at the machine level. In particular, we show how one can trade memory capacity for communication performance and vice-verse. We establish a new metric, that we call the ”quality” of a processing element that allow us to compare the scalability behavior of different systems.

By: José E. Moreira

Published in: RC24936 in 2010


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