Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!dsinc!bagate!cbmvax!daveh
From: daveh@cbmvax.commodore.com (Dave Haynie)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: A3000 CPU Wars!!
Message-ID: <22190@cbmvax.commodore.com>
Date: 5 Jun 91 21:07:20 GMT
References: <16888@helios.TAMU.EDU>
Reply-To: daveh@cbmvax.commodore.com (Dave Haynie)
Organization: Commodore, West Chester, PA
Lines: 36

In article <16888@helios.TAMU.EDU> aaf4808@venus.tamu.edu writes:

>Suppose you have threee systems seitting in front of you.
>One is an A3000 with 040 that disables motherboiard CPU.
>One is an A3000 wit 16 mhxzz with 040 that uses motherboard CPU.
>One is an A3000 25 mhz with 040 that uses motherboard CPU.

>All three run the same benchmark program.

>Which one is slowesrt and which one is fastest.? ?

That depends considerably on the system software, and what you're doing with 
the second processor.  Also depends alot on the benchmark.  If the second
processor is sleeping, 1 and 3 go fast, 2 a bit slower.  Most likely, no 
matter what you get the 68030 doing, it's not going to offset the faster
68040, so my **GUESS** would be that 1 is faster than 3.  Also, even with a
true SMP operating system, you aren't likely to split a process between
processors.  The existence of the second processor, though, implies that the
task load for the processor running your benchmark is less than for that of
the single processing system.  Since you have one 68030 and one 68040, you
aren't truely symmetric here anyway.  So even if SMD were available, it would
not likely apply here (neither UNIX nor AmigaOS support full symmetric 
multiprocessing now, though AT&T has announced plans for a future SVr4MP,
which will).  So the most likely use of the 68030 is as an assistant to the
OS in a more controlled fashion, which either AmigaOS or UNIX will support
just dandily.  For instance, if you ran the filesystem and device driver on the
68030, then the 68040 would be free of any disk management activities.  This
might not affect a CPU intensive benchmark, but it would affect a disk intensive
one.  You might have the 68030 manage X under UNIX, freeing the '040 of that
arduous task.  In any case, example 3 will be as fast or faster, depending on
the setup, as any of the others.  

-- 
Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
	"This is my mistake.  Let me make it good." -R.E.M.