Newsgroups: comp.parallel.mpi
From: wjiang@apollo.hp.com (Weicheng Jiang)
Subject: Re: PVMe/MPI comparison on SP2
Organization: Hewlett-Packard Corporation, Chelmsford, MA
Date: Sat, 13 Apr 1996 12:40:08 GMT
Message-ID: <DpswIw.1H7@apollo.hp.com>

In article <4kn227$k0f@server.cs.vt.edu> heagy@cs.vt.edu (Winfield S. Heagy) writes:
>Hi.  We recently completed an experiment to compare PVMe and MPI
>on the SP2.  The performace of MPI was far superior to PVMe on
>this platform.  These results confirm results we have seen in other
>papers.  Can anyone explain why PVMe has overall slower message
>passing times than MPI on the SP2?

When you pack your messages into the PVM buffer, you incur an extra memory-
to-memory copy and jeopardize the performance. To get the same performance
as MPI, you should use pvm_psend/pvm_precv, which is supported in the ORNL/UT
version of pvm3.3.10. Please refer to the following paper for a detailed
discussion of PVM performance on the SP2:

	http://www.netlib.org/utk/papers/pvmmpp.ps
	
Hope this information helps,

Weicheng Jiang
PVM Specialist, Hewlett Packard Co.




