Separate HTML for Basic Foil 31 More Examples of Collective Communication/Computation

Basic HTML version of Foils prepared 10 Oct 1995

Foil 31 More Examples of Collective Communication/Computation

From Fox Presentation Fall 1995 CPS615 Basic Simulation Track for Computational Science -- Fall Semester 95. by Geoffrey C. Fox

Four Processors where each has a send buffer of size 2

0 1 2 3 Processors

(2,4) (5,7) (0,3) (6,2) Initial Send Buffers

MPI_SENDRECV with 0,1 and 2,3 paired

(5,7) (2,4) (6,2) (0,3) Resultant Buffers

MPI_GATHER with root=0

(2,4,5,7,0,3,6,2) (_,_) (_,_) (_,_) Resultant Buffers

Four Processors where only rank=0 has send buffer

(2,4,5,7,0,3,6,2) (_,_) (_,_) (_,_) Initial send Buffers

MPI_SCATTER with root=0

(2,4) (5,7) (0,3) (6,2) Resultant Buffers