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From: mschedlb@hawk.ulowell.edu (Martin Schedlbauer)
Newsgroups: comp.parallel
Subject: Re: Hmm!
Summary: HyperCube is a connection scheme
Keywords: HyperCube, Parallel Connection Schemes
Message-ID: <3355@hubcap.UUCP>
Date: 26 Oct 88 17:30:20 GMT
Sender: fpst@hubcap.UUCP
Lines: 23
Approved: parallel@hubcap.clemson.edu

>  Is the Connection Machiene by ThinkingMachines Inc. a hypercube?
No it isn't. A hypercube is an architecture, in which nodes are connected to
their Gray-Code neighbours. Although, the new iPSC/2 uses a message routine
scheme called 'wormhole principle' where it is almost unimportant who's 
connected to whom, i.e. sending a message to a node which is not your neighbor
takes only less than 2% longer than sending it to your neighbor (routine is
done in hardware, not the O.S.) So, in effect the hypercube becomes a 'flat'
interconnection schemes (not multidimensional 'cubes'.)


>Is the "new" thing about Hypercubes the way they integrate many many
>processors, or the whole parallel processing idea?
The way they connect processors without using expensive crossbar switches and
still get decent message passing performance.

	...Martin


===========================================================================
Martin J. Schedlbauer
Dept. of Computer Science
University of Lowell
Lowell, MA 01854