Path: utzoo!attcan!uunet!husc6!mailrus!uwmcsd1!ig!agate!ucbvax!ucsfcgl!seibel
From: seibel@cgl.ucsf.edu (George Seibel)
Newsgroups: comp.arch
Subject: Re: missing Dhrystone 2.1 (1 of 3 &
Message-ID: <11053@cgl.ucsf.EDU>
Date: 21 Jul 88 07:23:57 GMT
References: <4232@cbmvax.UUCP> <76700035@p.cs.uiuc.edu> <1988Jul18.231331.19575@utzoo.uucp> <22406@amdcad.AMD.COM> <9amsvb52K11010cyawo@amdahl.uts.amdahl.com> <9a0K/cbluk1010IHSPc@amdahl.uts.amdahl.com>
Sender: daemon@cgl.ucsf.edu
Reply-To: seibel@hegel.mmwb.ucsf.edu.UUCP (George Seibel)
Organization: UCSF Computer Graphics Lab
Lines: 26

In article <9a0K/cbluk1010IHSPc@amdahl.uts.amdahl.com> chuck@amdahl.uts.amdahl.com (Charles Simmons) writes:

>Cray machines are optimized for programs that require lots of
>memory (say 1 Gbyte or so), floating point computations, and vector
             [???]                 [yes]                     [yes]
>computations.  Amdahl machines are optimized for smaller amounts
>of memory (say 256 Mbytes), and scalar processing that is
>non-floating-point intensive.  (These are my personal beliefs until
>I'm corrected by someone who knows more.)

What kind of Cray are we talking about here?  There are still some antique
Cray 1's out there with a grand total of ONE Mword!  (8 Mbyte)  The primary
use for these machines today is benchmarking by minisuper vendors ( :-))
Most Crays are XMPs with 2-8 Mword, a few 16 Mword.  (Most of the 8-16 Meg
X's have 4 processors, so there's not much memory per processor)  There are
a handful of Cray 2s with GOBS of memory - they didn't go over very well
compared to the X's.  The YMP is the latest unit - 8 processors, 32 Mwords.
The Cray 3 should be out soon, and will be a huge memory model.  But for the
time being, the typical Cray in the field is pretty strapped for memory.

>1)  An Amdahl mainframe is lots faster than a Vax 750.

I love this line.

George Seibel, UCSF
seibel@cgl.ucsf.edu