Cube GUI User Guide  (CubeGUI 4.5, revision 763326b)
Introduction in Cube GUI and its usage

Communication Efficiency (CommE) is the maximum across all processes of the ratio between useful computation time and total run-time:

CommE = maximum computation time / total run-time

CommE identifies when code is inefficient because it spends a large amount of time communicating rather than performing useful computations. CommE is composed of two additional metrics that reflect two causes of excessive time within communication:

These are measured using Serialization Efficiency and Transfer Efficiency. In obtaining these two sub-metrics we first calculate (using the Dimemas simulator) how the code would behave if run on an idealized network where transmission of data takes zero time.

These two sub-metrics combine to give Communication Efficiency:

CommE = Serialization Efficiency * Transfer Efficiency


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