Path: utzoo!attcan!uunet!husc6!think!ames!killer!tness7!bellcore!faline!sword!arrow!yba
From: yba@arrow.bellcore.com (Mark Levine)
Newsgroups: comp.arch
Subject: Wanted: bus speed information, general survey
Keywords: DMA bus speed
Message-ID: <849@sword.bellcore.com>
Date: 7 Sep 88 05:08:57 GMT
Sender: yba@sword.bellcore.com
Reply-To: yba@sabre.bellcore.com (Mark Levine)
Organization: Bellcore, Red Bank NJ
Lines: 23


I am interested in obtaining a survey of modern and expected-soon bus
speeds.  I would be interested in hearing from anyone who has a good
survey, knows where to find a list of bus architectures and transfer
rates, etc.

My purpose will be to compare moving bits across a computer bus with
other paradigms for moving computer data about (like a Local Area
Network).  Bus limit(s) imposed by DMA hardware, maximum burst rates,
or contention is useful information.  (Example: folklore has it the VME
bus could go at 160 MB/sec if ALL the controllers were designed to
cooperate, but practically VME always goes at a small fraction of
that).

How bold a statement is "the 60 MB/sec I/O throughput rate of a DEC
6200 is about as fast as we can expect to see for a few years in the
workstation/mini/super-mini class" (whatever that class is, mostly
under $1M)?  How many things are out there reliably pumping over 150
Mb/s?  Are manufacturer's quoted speeds inflated by the width of the
bus, number of processors, or assumptions about contention?  Quotable
sources appreciated, but not required.

Is this an appropriate place to ask?  Any better pointers?