Cube GUI User Guide  (CubeGUI 4.8-rc1, revision e0742334)
Introduction in Cube GUI and its usage

Communication Efficiency

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

\begin{eqnarray*}CommE=maximum\; across\; processes(\frac{computation\; time}{total\; runtime}) \end{eqnarray*}

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 Serialisation Efficiency and Transfer Efficiency. Combination of these two sub-metrics gives us Communication Efficiency:

CommE = Serialisation EfficiencyTransfer Efficiency

To obtain these two sub-metrics we need to perform Scalasca trace analysis which identifies serialisations and inefficient communication patterns.


Cube Writer Library    Copyright © 1998–2022 Forschungszentrum Jülich GmbH, Jülich Supercomputing Centre
Copyright © 2009–2015 German Research School for Simulation Sciences GmbH, Laboratory for Parallel Programming