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Publications of SPCL
|R. Riesen, C. Vaughan, a. Torsten Hoefler:|
|What if MPI Collective Operations Were Instantaneous?|
(In Proceedings of the 2006 Cray User Group Meeting, presented in Lugano, Switzerland, May 2006)
AbstractCollective MPI operations are an interesting research topic, since their implementation is complex and there are many different possible ways to improve their performance. It is not always obvious how much a given application will gain from such improvements and some of the methods to improve collective performance are costly and time-consuming to implement. In this paper we use a hybrid MPI simulator to run benchmarks and applications with the cost of collective operations set to zero. This allows us to gather performance data that shows how much at most an application could benefit from better collective operations.