Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!rphroy!kyzyl!tkacik
From: tkacik@kyzyl.mi.org (Tom Tkacik)
Newsgroups: comp.sys.3b1
Subject: Re: Hardware freaks Unite (on this one)
Keywords: 3B1, cache, hardware project suggestion.
Message-ID: <326@kyzyl.mi.org>
Date: 22 Apr 91 10:33:22 GMT
References: <1991Mar26.023948.3966@i88.isc.com> <6386@acorn.co.uk> <101@fbits.ttank.com>
Organization: Somewhere in Royal Oak, MI
Lines: 20

In article <101@fbits.ttank.com>, Mariusz@fbits.ttank.com (Mariusz Stanczak) writes:
>                    A cache would be a much less obtrusive way to boost
> a little the, already adequate, performance of this machine, with full
> compatibility assured.  ...it'd be cheaper too ;-) (well maybe not, 25ns
> memory still isn't a commodity item, but SIMPLER it would be for sure!)

A drop in cache would be an expensive way not to gain any performance
at all in a 3b1.  A cache is simply a way to make main memory look
faster.  It works well on machines whose processor can use 25ns memory,
but have to settle for cheaper 80ns main memory.  A litte 25ns cache can
make megabytes of 80ns memory look faster.

On the 3b1 all of the memory runs at full speed.  The 68010 does not use
any wait states, (even for expansion memory).  A cache
cannot speed  it up at all.  Just think of your 3b1 as already having
4Meg of cache.
-- 
Tom Tkacik                |
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