Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!endor!reiter
From: reiter@endor.harvard.edu (Ehud Reiter)
Newsgroups: comp.arch
Subject: Connection Machine
Message-ID: <3516@husc6.harvard.edu>
Date: 10 Dec 87 19:46:48 GMT
Sender: news@husc6.harvard.edu
Reply-To: reiter@harvard.UUCP (Ehud Reiter)
Organization: Aiken Computation Lab Harvard, Cambridge, MA
Lines: 25

The Connection Machine is usually presented as 64,000 1-bit SIMD processors
hooked up with a hypercube router.  However, from talking to a few people who
have experience with it (the CM2, not the CM1), I get the impression that many
applications basically ignore the 1-bit processors and the hypercube router
(which is very slow - it takes 1 ms to send a message), and instead do all
their computing with the 2000 Weitek FPU's, and do all their communicating
with the "NEWS" system, which basically is a fast 2-D mesh interconnect.

That is, the alternative model of the Connection Machine which these
applications use is that it is a 2-D mesh of 2000 fast FPU's, backed by
512MB of memory and a very high bandwidth disk I/O system.  Like a
modern-day version of the Illiac IV, I guess (but one that actually works,
unlike the Illiac).  To me, anyways, this "Illiac" model seems much more
useful (for getting real work done) than the "hypercube" model.

My question is, how do people who are running real applications on the CM2
use it?  Does anyone who actually has a CM care to comment?  I realize that
there is one serious application, the news-wire retrieval program, which does
use the 1-bit CPU's to do its communicating (although it doesn't use the
hypercube router very much) - are there other (commercial) applications
which use either the 1-bit CPU's or the hypercube router?

					Ehud Reiter
					reiter@harvard	(ARPA,BITNET,UUCP)
					reiter@harvard.harvard.EDU  (new ARPA)