Tim,
The collective in Open MPI works differently than in MPICH. They are
dynamically selected based on the number of processes involved and the amount
of data to be exchanged. Therefore, it is difficult to answer your question
without knowing this information.
There are 4 algorithms for MPI_A
Dear OpenMPI Developers,
I would be grateful if someone could briefly describe the cost
(complexity) for the allgatherv() collective operation in the current
release of OpenMPI.
For MPICH2 I believe the cost is ceiling(lg p). Can anyone comment on
the algorithms and cost used in the OpenMPI
