Xing Feng,
A more focused (and certainly more detailed) analysis of the cost of
different algorithms for collective communications can be found in [1], and
more recently in [2].
George.
[1]
http://icl.cs.utk.edu/projectsfiles/rib/pubs/Pjesivac-Grbovic_PMEO-PDS05.pdf
[2] https://www.cs.utexas.e
Dear Xing Feng,
there are different algorithms to implement collective communication
patterns. Next to general Big-O complexity the concrete complexity
also depends on the network topology, message length, etc..
Therefore many MPI implementations switch between different algorithms
depending on t
