Newsgroups: comp.sys.hp
Path: utzoo!utgpu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!alchemy.chem.utoronto.ca!system
From: system@alchemy.chem.utoronto.ca (System Admin (Mike Peterson))
Subject: Re: A benchmark
Message-ID: <1991May10.194937.20420@alchemy.chem.utoronto.ca>
Organization: University of Toronto Chemistry Department
References: <1991May3.023705.5616@marlin.jcu.edu.au> <5570629@hpfcdc.HP.COM> <1991May9.155313.8671@midway.uchicago.edu>
Date: Fri, 10 May 1991 19:49:37 GMT

In article <1991May9.155313.8671@midway.uchicago.edu> rtp1@quads.uchicago.edu (raymond thomas pierrehumbert) writes:
>So, we have a problem here.  How do we reconcile HP's published
>float performance figures with the results on this real
>scientific model code?  Do we perhaps have a compiler that
>can do Linpak and specfp efficiently but nothing else?  That
>certainly was the case on my DN10k, for example, where the
>10.6 fortran compiler clearly had some kludges in it that
>had the sole effect of making compiled BLAS run faster (and
>just about nothing else).

While I agree about the Apollo DN10k compiler having stuff in it to run
LINPACK much faster, my general experience with the DN10000, IBM
RS/6000 320, SGI 4D2x0 and HP 720 would put the floating point
performance in the following order:

DN10000    ~5 Mflops/cpu with 10.7 compiler
4D2x0      ~5 Mflops/cpu
6000/320   ~8 Mflops
720        ~15 Mflops with compiler now on demo models

This is based on relative performance on an ab initio quantum chemistry
package (basically a subset of Gaussian 8x) looking only at cpu-intensive
jobs, and assuming 5 Mflops for DN10000/4D210 (as LINPACK would report).
It agrees pretty well with the vendor claims too (hard as that may be to
believe :-) ). We have, however, found specific codes that run much
faster and much slower (i.e. up to factors of 2 easily) than these
general guidelines on all the systems except the 720 (not enough time
to throw a wide variety at it :-( ).

Mike.
-- 
Mike Peterson, System Administrator, U/Toronto Department of Chemistry
E-mail: system@alchemy.chem.utoronto.ca
Tel: (416) 978-7094                  Fax: (416) 978-8775