Newsgroups: comp.parallel.mpi
From: Panagiotis Melas <pm95r@ecs.soton.ac.uk>
Subject: Bcast impmelmentation on SP2/mpich
Organization: University of Southampton
Date: Wed, 15 Apr 1998 19:45:57 +0000
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Message-ID: <35350E75.C0C490D1@ecs.soton.ac.uk>

Does anybody know whether the broadcast implementation of MPI Bcast is
based on a binomial tree or not for the IBM SP2?

I have some results that show rather a sequential tree...
	
	size/nodes: 	2	3 	4	5	6 
	  1K		157	181	305	312	333 (us)
	  2K		204	272	384	410	483
	  4K		275	404	589	652	756
	  8K		522	814	1234	1487	1789
	 16K		836	1432	2179	2771	3411 			
	
	
Thanks for any suggestions
-- 
P. Melas

pm95r@ecs.soton.ac.uk