From: salo@cray.com (Eric Salo)
Newsgroups: comp.parallel.mpi
Subject: Re: SGI Origin 2000 Memory Bandwidth???
Date: 18 Feb 1999 07:16:54 GMT
Organization: Silicon Graphics, Inc.
Message-Id: <7agep6$la6$1@walter-fddi.cray.com>
References: <7acjdj$cst@news.jhu.edu>
Xref: ukc comp.parallel.mpi:4645


There's really no simple answer to a question like this on a machine
as complex as an Origin, but the bottom line is that you shouldn't
expect to see more than ~120 MB/sec for uncached MPI transfers on
current hardware.

>SGI technical documentation claims 630 MB/sec sustained memory bandwidth.
>
>Is this best case or worst case? Is there a guarantee for the bandwidth
>between the two processors that are the furthest away?
>
>What does this mean in terms of MPI? If I am only seeing ~200 MB/sec with 65
>kB messages, is that good?