> < ^ Date: Tue, 26 Jan 1993 18:18:15 +0100
> < ^ From: Martin Schoenert <martin.schoenert@math.rwth-aachen.de >
> < ^ Subject: GAPstones

Here is a selected list of GAPstones for various machines.
Computer Model MHz Memory OS Compiler GAPstones by

Atari        ST520+  8    4 MB  TOS     gcc 2.1      1168       M. Schoenert

Apollo       DN10000 ?       ?  SR10.3  ?           20625       R. Lewis

DECstation   3100   20   32 MB  Ultrix  gcc 2.2     22590       M. Schoenert
DECstation   5120   25   32 MB  Ultrix  gcc 2.2     24942       M. Schoenert

IBM PC       386SX  16       ?  DOS     djgpp 1.05   1607       S. Linton
IBM PC       386DX  33       ?  DOS     djgpp 1.05   6057       S. Rosenbrock
IBM PC       486DX  33       ?  DOS     djgpp 1.05   9948       L. Soicher
IBM PC       486DX  50   16 MB  386BSD  gcc 2.3.3   32894       M. Schoenert
IBM PC       486DX  50   16 MB  DOS     djgpp 1.09 ~32000       M. Schoenert

IBM RS6000   950   ~40    lots  AIX     cc          41691       R. Dentzer

HP           730    67  128 MB  HP-UX 8 cc          63578       M. Schoenert

NeXTstation         25       ?  Mach    ?           16484       G. Mess

Sparc        4/280  40   32 MB  SunOs   gcc 2.1     15145       R. Dentzer
SparcStation SLC     ?       ?  SunOs   ?           11962       M. Smith
SparcStation SLC     ?   12 MB  SunOS   ?           12477       D. Endico
SparcStation SLC    20   16 MB  SunOs   gcc 2.1     15272       R. Dentzer
SparcStation 1+      ?       ?  SunOs   ?           14203       W. Nickel
SparcStation 1+      ?       ?  SunOs   ?           15032       M. Smith
SparcStation 1+      ?       ?  SunOs   ?           16739       D. Sibley
SparcStation 1+     25   24 MB  SunOs   ?           17758       R. Dentzer
SparcStation ELC     ?       ?  SunOs   ?           19821       M. Smith
SparcStation IPX     ?   64 MB  SunOS   ?           23782       D. Endico
SparcStation 2       ?       ?  SunOS   ?           24013       A. Caranti
SparcStation 2      40   32 MB  SunOS   gcc 2.1     27888       R. Dentzer
SparcStation ?       ?   64 MB  SunOS   ?           39772       A. Kaup
SparcStation 10-20  33   32 MB  SunOS   gcc 2.1     47619       R. Dentzer
SparcStation 10-31   ?       ?  SunOs   ?           44917       M. Smith
SparcStation 10-30   ?       ?  SunOS   ?           48329       W. Nickel

A few remarks:

The Atari ST520+ is the slowest machine. It is more than a factor of 50
slower than the fastest machine (a HP 730). Note that quite a bit of
development of GAP was done on this machine (it is the one I have at
home). Compilation (with optimization) of the entire GAP kernel takes
over 4 hours on this machine.

There is a big difference between L. Soicher's result for a 486DX33 and
our result for 486DX50. One would expect that the 486DX50 is 50% faster,
but not that it is more that 3 times faster. The reason is the
following. In regular intervals (actually whenever a loop body is
executed) GAP checks whether the user wants to interrupt the computation.
Under UNIX this means checking a variable that is set by the signal
handler for '<ctr>-C'. Unfortunatly this is not possible under DOS/GO32
(or is it? 'setcbrk' might do what we want, but the documentation of
DJGPP only says that there is such a function, not what it does). Thus
under DOS GAP checks whether the user has pressed a key, and if so,
whether it was '<ctr>-C'. Now checking whether a key was pressed
requires a system call ('kbhit()'), which means that GO32 (the DOS
extender) has to switch from protected mode (in which GAP runs) to real
mode (which DOS wants). This is a *very* expensive operation. So
expensive, that GAP 3.1 spent more than half of the time it took to
execute 'combinat.tst' switching from protected mode to real mode and
back again. In 3.2 we have changed GAP so that only every 20th check
actually does call 'kbhit()'. This made GAP more than a factor of 2
faster. And the time between pressing '<ctr>-C' and GAP responding
is still small enough.

The results for SparcStations vary somewhat. I think this has to do with
the compiler used. GNU CC 2.x seems to be best.

The NeXTstation is actually faster than the above result would indicate.
Namely, one has to use GNU CC 2.x, instead of the compiler that comes
with the operating system, which is GNU CC 1.39 (I think). However,
installation of GNU CC 2.x is not a trivial task (or so I am told, there
seems to be some problem with precompiled header files).

Martin.

-- .- .-. - .. -.  .-.. --- ...- . ...  .- -. -. .. -.- .-
Martin Sch"onert,   Martin.Schoenert@Math.RWTH-Aachen.DE,  +49 241 804551
Lehrstuhl D f"ur Mathematik, Templergraben 64, RWTH, D 51 Aachen, Germany

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