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From: alan@mn-at1.UUCP (Alan Klietz)
Newsgroups: net.arch
Subject: Re: VERY LARGE main memories
Message-ID: <145@mn-at1.UUCP>
Date: Thu, 28-Aug-86 03:15:10 EDT
Article-I.D.: mn-at1.145
Posted: Thu Aug 28 03:15:10 1986
Date-Received: Fri, 29-Aug-86 05:44:54 EDT
References: <2017@sdcsvax.UUCP> <884@gilbbs.UUCP>
Lines: 23
Keywords: memory size

In article <884@gilbbs.UUCP>, mc68020@gilbbs.UUCP (Thomas J Keller) writes:
> 
>    Someone please correct me if I am wrong, but as I have been lead to 
> understand the situation, it will prove somewhat difficult to successfully
> implement large physical memory systems on the order of 1Gb.  The primary
> impediment seems to be the delays caused by propagation delays in the
> decoding trees.   Anyone care to enlight me (us)?
> 

If you use DRAMs you have access times on the order of 50-200ns.  That is
enough time for fast ECL-type logic to do plenty of decoding.

The CRAY-3 is rumored to have a central memory on the order of 2 Gwords, and
solid-state "disks" are going even higher.
--
Alan Klietz
Minnesota Supercomputer Center (*)
1200 Washington Avenue South
Minneapolis, MN  55415    UUCP:  ..ihnp4!dicome!mn-at1!alan
Ph: +1 612 638 0577              ..caip!meccts!dicome!mn-at1!alan
                          ARPA:  aek@umn-rei-uc.ARPA

(*) An affiliate of the University of Minnesota