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Path: utzoo!watmath!clyde!caip!think!mit-eddie!genrad!decvax!mcnc!jnw
From: jnw@mcnc.UUCP (John White)
Newsgroups: net.arch
Subject: Re: paging and loading
Message-ID: <488@mcnc.mcnc.UUCP>
Date: Mon, 20-Oct-86 22:37:50 EDT
Article-I.D.: mcnc.488
Posted: Mon Oct 20 22:37:50 1986
Date-Received: Wed, 22-Oct-86 03:41:54 EDT
References: <949@usl.UUCP>, <5100148@ccvaxa> <7232@utzoo.UUCP>
Organization: Microelectronics Center of NC; RTP, NC
Lines: 16
Summary: RAMdisk paging devices make sense

In article <7232@utzoo.UUCP>, henry@utzoo.UUCP (Henry Spencer) writes:
> ... If I remember it correctly --
> I'm not sure of this -- the 3090 is paging out of ordinary RAM, which they
> would have preferred to make directly addressable except that they are
> constrained by backward compatibility and not enough address bits.  This
> is a kludge, not something that is likely to become widespread.
> -- 
> 				Henry Spencer @ U of Toronto Zoology
> 				{allegra,ihnp4,decvax,pyramid}!utzoo!henry

With memory prices dropping, it makes some sense to use a RAMdisk as the
paging device on a high performance system. The RAMdisk can use slower,
less expensive memory. Also, the main memory bus can be driven much faster
if it is known that there will be no more than, say, 500 memory chips on it.
The RAMdisk, on the other hand, could have more than 50,000 chips.
-jnw@mcnc