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From: eugene@pioneer.arpa (Eugene Miya N.)
Newsgroups: comp.arch
Subject: Re: What is with these Vectors anyways?
Message-ID: <2418@ames.arpa>
Date: Tue, 28-Jul-87 21:36:56 EDT
Article-I.D.: ames.2418
Posted: Tue Jul 28 21:36:56 1987
Date-Received: Thu, 30-Jul-87 04:26:46 EDT
References: <218@astra.necisa.oz> <142700010@tiger.UUCP>
Sender: usenet@ames.arpa
Reply-To: eugene@pioneer.UUCP (Eugene Miya N.)
Organization: NASA Ames Research Center, Moffett Field, Calif.
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In article <373@astroatc.UUCP> johnw@astroatc.UUCP (John F. Wardale) writes:
>Someone asked about "mainframe" vs "super-computer"
>
>In my mind, "super-computers" are good floating point, and are
>likely to be strange (specialized) beasts.
>A mainframe is a big, fast, reliable, machine.  (Great at running
>drystones, and/or zillions of users) 
>(Yes, a brand X computer could be a mainframe for one site, and a
>"super-computer" for another, but generally isn't)

Reliable?  (well sort of...)  and NO.  Supercomputer is not a term
relative to a site, it is relative to a period of time like now, or 20
years ago when a 7600 was a super.  Only IBM would give you the brand X
line.

>In article <10956@amdahl.amdahl.com> littauer@amdahl.UUCP (Tom Littauer) writes:
>
>This is why the "Crays" ar "supers" and the "IBMs" are "mainframes."
>
>> If you could get it, you'd want a machine fast enough to do EVERYTHING
>> quickly, not just a subset of things.
>
>Yes, but all these machine have engineering tradeoffs to "tune"
>them for the market nitch they were designed for.  (This tuning
>starts in the Architacture, and continued thru the gate-level design.)

One area where the IBM excell over the VAXen and SUN and where the Crays
and Cybers excell over the IBMs is in the area of I/O.  Basically
(gross-oversimplification), VAXen are tied to the UNIBUS, MASSBUS, and
SBI [yes yes BI, CI, etc.].  IBM has the "Channel."  Crays and Cybers
have propritary (until recently) channels of even higher bandwidth.
These big machines also do disk stripping  (Note: I have only seen two
major papers on the performance of stripping, some PhD thesis are
possible here).  One of the reasons the Japanese machines are not
popular is that they have few peripherals to things like Hyperchannel
interfaces.  (As well as batch operating systems: ACOS or more IBM
flavored things.)  I also have an interesting paper on IOStone from the
guys who brought the massive memory VAX.

Basically, I'll just read this discussion.  You guys are on the right
track.  On to SIGGRAPH.

P.S. I have asked one of the two men who defined the Class scheme of
rating computers "Have we reached Class 7 with the ETA-10?"  He's at
LLNL.  He said NO.  I have to call the other one.  (And Neil if you are
reading this, George wants to talk to you.).

From the Rock of Ages Home for Retired Hackers:

--eugene miya
  NASA Ames Research Center
  eugene@ames-aurora.ARPA
  "You trust the `reply' command with all those different mailers out there?"
  "Send mail, avoid follow-ups.  If enough, I'll summarize."
  {hplabs,hao,ihnp4,decwrl,allegra,tektronix,menlo70}!ames!aurora!eugene