Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Do MPI collective operations involve multiple hops?

  1. May 7, 2013 #1
    Consider the reduce operation for example. Do all nodes send data directly to the root? Or is there some structure where a node will recieve data from a few other nodes, perform a reduction, then pass the intermediate results to other nodes?
  2. jcsd
  3. May 7, 2013 #2
    Sth like that could be achieved in two steps using appropriate grouping and using MPI_ALLREDUCE (instead of MPI_REDUCE) first

    Pls attend:
    http://www.mpi-forum.org/docs/mpi22-report/node109.htm#Node109 [Broken]
    Collective Communication - 86. Introduction and Overview
    Last edited by a moderator: May 6, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Do MPI collective operations involve multiple hops?
  1. FFTW and MPI (Replies: 4)

  2. MPI in Fortran (Replies: 2)

  3. MPI Bcast (Replies: 3)