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Subject: [OMPI users] Algorithms used in MPI_BCast
From: Mohammed El Mehdi DIOURI (mehdi.diouri_at_[hidden])
Date: 2012-09-20 20:13:21


Hi,

I would like to know what are the algorithms used in MPI_BCast() in the OpenMPI implementation.

For example, in MPICH2, depending on the number of processes and the size of data to broadcast, the broadcasting algorithm used can be different : a binomial tree if the message is short or MPI_Scatter followed by MPI_AllGather if the message to broadcast is long.

Is it the same for OpenMPI ?
It doesn't seem to be the case since the broadcasting time is different when I use OpenMPI or MPICH2.

Thanks for your help,

Mehdi.