Newsgroups: comp.parallel.mpi
From: s_straub@ira.uka.de (Matthias Straub)
Subject: Q: derived data types and isend
Organization: University of Karlsruhe, Germany
Date: 3 Oct 1996 10:24:52 GMT
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Message-ID: <53049k$lm6@nz12.rz.uni-karlsruhe.de>

I'm wondering how indexed derived data types effect
performance, considering:
You can't expect the communication-hardware to do the indexing,
so MPI would probably copy the indexed data into a linear buffer and
transfer this as usual. But what if immediate-sends are
used ( which I plan to do)? There is no buffering - so does MPI have to 
transfer the indexed data word by word?
How about performance compared to 'manually' copying the indexed data 
into a buffer via a do-loop?
Any help appreciated.

	Matthias Straub

BTW. hardware is a SP2 and a Power Challenge

--
Matthias Straub, Student at Universitaet Karlsruhe, Comp. Science Dept.
URL  : http://www.rz.uni-karlsruhe.de/~uk6a
email: s_straub@ira.uka.de 

