Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!rochester!pt.cs.cmu.edu!gandalf.cs.cmu.edu!lindsay
From: lindsay@gandalf.cs.cmu.edu (Donald Lindsay)
Newsgroups: comp.arch
Subject: Re: Don't look back...
Message-ID: <4330@pt.cs.cmu.edu>
Date: 22 Feb 89 04:47:34 GMT
References: <747@atanasoff.cs.iastate.edu> <28200275@mcdurb> <4290@pt.cs.cmu.edu> <13582@winchester.mips.COM>
Organization: Carnegie-Mellon University, CS/RI
Lines: 23


John Mashey has argued convincingly that single-chip processors are on a
faster trend curve than mainframe processors, and in fact are just plain
catching up.

The basic reason is the speed of light. As Mr. Cray knows, small == fast.
In the long run, the smallest system is the one that fits on a single
chip.

Now that you've all nodded sagely ... I don't agree with the last
sentence above. I think that we're going to see really large chips -
perhaps the much fabled wafer-scale integration. And if you think about
wire lengths, those chips are going to have some awfully long
interconnects: wires just centimeters and centimeters long. We might do
better by going to three dimensions instead of two.

The breakthrough I'd like to see, is chip vias. For the hardware-
impaired, what I mean is, I'd like to see signal paths between the two
surfaces of a chip. I'd like to take a stack of naked chips, and then
solder them together into a solid cube.

-- 
Don		D.C.Lindsay 	Carnegie Mellon   Computer Science
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