Path: utzoo!utgpu!water!watmath!clyde!bellcore!rutgers!umn-d-ub!umn-cs!hall!blu
From: blu@hall.cray.com (Brian Utterback)
Newsgroups: comp.arch
Subject: Re: Cray & Amdahl (Was: missing Dhrystone 2.1)
Message-ID: <7819@hall.cray.com>
Date: 22 Jul 88 17:34:27 GMT
References: <4232@cbmvax.UUCP> <76700035@p.cs.uiuc.edu> <5342@june.cs.washington.edu> <60952@sun.uucp>
Reply-To: blu@hall.UUCP (Brian Utterback)
Organization: Cray Research, Inc., Mendota Heights, MN
Lines: 20

In article <60952@sun.uucp> dre%ember@Sun.COM (David Emberson) writes:
>If money is no object, it makes sense to buy a ton of memory AND have VM.
>This may be apocryphal, but I have been told that Seymour Cray, replying to
>the question of why the Cray 1 did not have virtual memory, replied, "Because
>I don't understand it."

I have never heard anything of the kind.  Well, sort of the kind.  What he
did say was that the CDC machines used ones-complement arithmetic instead of
twos-complement because he did not understand it.  He went on to say that
he figured it out by the time he built the Cray-1, since it is twos-complement.
I tend to think that he was joking.  By the way, this is anecdotal rather
than apocryphal because the talk was video taped and I have seen it.

Cray's continue to use only physical memory rather than virtual for one reason:
it's faster.  That's our charter: faster.
-- 
Brian Utterback     |UUCP:{ihnp4!cray,sun!tundra}!hall!blu |  "Aunt Pheobe, 
Cray Research Inc.  |ARPA:blu%hall.cray.com@uc.msc.umn.edu |  we looked like
One Tara Blvd. #301 |                                      |    Smurfs!"
Nashua NH. 03062    |Tele:(603) 888-3083                   |