Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!ut-sally!husc6!cmcl2!rna!cubsvax!peters
From: peters@cubsvax.UUCP (Peter S. Shenkin)
Newsgroups: net.arch
Subject: Re: VERY LARGE main memories; HOW M
Message-ID: <553@cubsvax.UUCP>
Date: Sat, 4-Oct-86 18:57:46 EDT
Article-I.D.: cubsvax.553
Posted: Sat Oct  4 18:57:46 1986
Date-Received: Tue, 7-Oct-86 19:16:46 EDT
References: <1128@tekig5.UUCP> <5100141@ccvaxa> <amdcad.13214>
Reply-To: peters@cubsvax.UUCP (Peter S. Shenkin)
Organization: Columbia Univ. Bio. CG Fac., NY
Lines: 33

In article <amdcad.13214> phil@amdcad.UUCP (Phil Ngai) writes:

>There was a claim that RAM is getting cheaper than disk. Assume 474Mb
>eagle at $10,000. This yields $2E-5 per byte. Assume 256Kbit DRAM at
>$2.56. (see 10/1/86 San Jose Mercury News Fry's Electronics ad) This
>yields $8E-5 per byte.
>
>Rotating machinery is still cheaper than silicon.

And the advent of R/W optical disks will make this truer;  even though you
can only write once, and access is basically sequential, a large part of
their use will be to replace disk rather than tape.  For instance, I'm 
now sitting on about 10Mb of data coughed up by molecular mechanics programs;
I have to look at this stuff again and again, reanalysing it in the light
of what I never thought of before, in order to make sense of it.  My continually
changing analysis programs will continue to reside on our Eagle, but as soon
as we get our optical disk (hopefully this year) all this stuff can be moved
onto it.  Our facility also does optical image processing, and the situation
is similar; we have a 36Mb image library on the Eagle.  We also have groups
of people doing pattern-matching on protein and nucleic acid
sequences;  the library for this info is also huge, and is on the Eagle.
In fact, the entire Brookhave National Lab's Protein Data Bank is something
we desperately need to have on line all the time, but can't because we don't
have room.  We spend large amounts of time moving files in from tape and
deciding wwhich ones to delete.  Thus we're going to have the distinction
between static and updatable on-line storage, and the static storage is going
to be cheaper than the dynamic.  Also, since the cost of the medium itself is
negligible (as opposed to the cost of the machine that reads and writes on it),
static doesn't even have to be THAT static;  all the manual pages can go on
it, for instance.

Peter S. Shenkin	 Columbia Univ. Biology Dept., NY, NY  10027
{philabs,rna}!cubsvax!peters		cubsvax!peters@columbia.ARPA