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From: avie@cmu-cs-wb1.ARPA (Avadis Tevanian)
Newsgroups: net.arch
Subject: Re: Re: Caltech's Cosmic Cube
Message-ID: <166@cmu-cs-wb1.ARPA>
Date: Sat, 16-Feb-85 22:57:00 EST
Article-I.D.: cmu-cs-w.166
Posted: Sat Feb 16 22:57:00 1985
Date-Received: Wed, 20-Feb-85 04:55:53 EST
References: <333@oakhill.UUCP> <21294@lanl.ARPA>, <7268@watrose.UUCP>
Organization: Carnegie-Mellon University, CS/RI
Lines: 15

This Cosmic Cube is really puzzling me... As I understand it, each processor
has its own local memory, no memory is shared.  Rather, message passing is
used for communications.

What puzzles me is why use point to point channels between processors (and
do routing if a connection does not exist)?  Wouldn't it be much simpler to
use a dedicated ethernet?  A 10mb ethernet should easily provide the
necessary bandwidth for 64 or more processors.  Since the ethernet would be
dedicated, minimal protocols could be used, thus keeping the costs of
managing the ethernet down.  If 10mb is not enough bandwidth (which I highly
doubt), it shouldn't be too tough to increase the bandwidth considering that
the wire will be dedicated and can be very short (it won't need to run all
around a building).

	Avie Tevanian