Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!udel!burdvax!barry
From: barry@PRC.Unisys.COM (Barry Traylor)
Newsgroups: comp.arch
Subject: Re: more soap box
Summary: Not close.  No cigar.  What's the point?
Keywords: micro, mini, mainframe
Message-ID: <11538@burdvax.PRC.Unisys.COM>
Date: 24 Sep 89 06:39:06 GMT
References: <21962@cup.portal.com> <1989Sep12.031453.22947@wolves.uucp> <22130@cup.portal.com> <1989Sep16.044013.429@wolves.uucp> <259@ssp1.idca.tds.philips.nl> <22308@cup.portal.com> <7981@cbmvax.UUCP>
Followup-To: comp.arch
Organization: Unisys Corporation, Paoli Research Center; Paoli, PA
Lines: 30

In article <7981@cbmvax.UUCP> jesup@cbmvax.UUCP (Randell Jesup) writes:
>
>	Well, I just tried it on my machine (old, slower disk controller,
>medium fast SCSI disk (Quantum)).  Read 3Meg file into memory: 609K/s.
>Copy 3 meg file (on slightly fragged partition) to another file on the
>same disk partition: ~550K/s.  On a newer controller with a fast SCSI disk
>(170Meg CDC): ~900K/s and ~800K/s.

Ok, ok, so we've now seen two pretty impressive transfer rates for MICROs.
I would even go so far as to say that the rates reported beat by a little
the PDP11/70 I used 10 years ago.  I hope, however, that you don't think
this comes even close to what is attainable SUSTAINED on a mainframe.  How
much of the CPU was chewed up while these transfers were underway?  I have
seen mainframes do 50 times that rate (on a 1 processor system) and only
utilize 10% of a CPU.  I have seen I/O rates at 4000-5000 i/os per second
where the CPU is less than 75% utilized.  How many SCSI channels do these
micros support?  On a strict connectivity basis, the mainframe I am
associated with can support over 100!

So go ahead and feed steriods to SCSI.  It will help mainframes as much as
everyone else.  We would love to sell our mainframe customers hundreds of
the things to squeeze into their pack farm acherage.

These are my opinions and in no way can be construed as those of Unisys
Corp.  (Well, one CAN construe them any way one wants, I don't contstrue
them as representing the Corp., however. ;-) )

Barry Traylor
Unisys A Series Engineering
barry@prc.unisys.com (when I can dial in AND the line stays up)