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Date:Mon May 19 17:35:57 1995 
Subject:fastest processor for running Poplog? 
From:A . Sloman 
Volume-ID:950520.03 

At present the fastest processor we have on which we run Poplog is
the Ross Hypersparc 66Mhz. It is now possible to buy 100 Mhz
hypersparcs and I hear that 125 Mhz models will shortly be
available.

Does anyone know how these compare with other machines that Poplog
runs on? E.g. what about the fastest currently available HP machine,
or SGI machine or Dec Alpha (alas I gather only VMS poplog is being
ported to the Alpha?)

I shall shortly have to buy a compute server for a research project
using Poplog so any user experience on this would be helpful.

I can provide some comparative figures on machines I have tested using a
simple Poplog prolog benchmark and two simple Pop-11 benchmarks, as
follows:

                     A      B   C       D     E      F    G     H       I
                    DEC         HP     Sun*  Sun    Sun  Sun   Sun     Sun
                    3100   MIPS HP-UX  SS2   SS/    SS10 SS10  SS10    Ross
                           2000 M68040       672    /30   /41   /52    HS66
                                                              Sol2.3   mhz
---------------------------------------------------------------------------
Prolog test KLips    56.1  68.9 107.8 117.0  134.8 203.3 238   295     335
(Simple reverse)
---------------------------------------------------------------------------
Pop-11 Factorial(1000)
three times (Secs)
    recursive       0.78  0.80  0.55   0.81  0.75  0.55  0.46  0.42   0.38
    iterative       0.77  0.80  0.57   0.78  0.71  0.51  0.45  0.40   0.38
---------------------------------------------------------------------------
Floating point
    single (secs)   0.88  0.67  0.71   0.38  0.38  0.21  0.19  0.17   0.13
    double          1.05  0.85  0.60   0.43  0.41  0.25  0.22  0.18   0.16
---------------------------------------------------------------------------

* Replacing SS2 processor with Weitek chip gave
    177 Klips, Factorial: 0.5, 0.45 secs, Float: 0.23, 0.3 secs
    I.e. not quite SS10/30

For the Prolog test, the bigger the number the better. For all others,
the smaller the number the better. Note that the Poplog prolog compiler
contains no special optimisations for the naive reverse benchmark, so
this can't be compared with figures for other Prolog systems!

WARNINGS:

a. Benchmarks should always be taken with a pinch of salt. These all
   use internally measured CPU time, not elapsed time. Also because of
   the unpredictability of Unix I ran the programs several times and
   took the best results, rather than averaging, as I was trying to
   assess relative (maximum) speeds of processors.

b. There were several programs running on some of the machines when I
    did the tests (Unix is hard to control anyway).

c. The values in column H were on a machine running Solaris 2.3. All
   the other suns were using SunOS 4.1.3 (or earlier).

I assume the Ross Hypersparc values would scale roughly with clock
speed. I.e. for 125 MHz the figures would be:
    639 Klips, Factorial 0.20, 0.20 secs, Float 0.068 0.084 secs

Comparison with new 70Mhz and 90Mhz Supersparc is hard to guess.

I don't assume that published Specint or Specfp figures are necessarily
an accurate guide to Poplog performance because CPU specific
optimisations that Compiler writers do for other compilers may not be
done in Poplog.

Any ideas about new HP, SGI, or DEC Alpha? Any experience of reliability
or service also welcome.

Any gueses regarding Ultrasparc ????
Aaron