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From: EOAHMAD%NTUVAX.BITNET@cunyvm.cuny.edu
Newsgroups: comp.os.minix
Subject: Re: minix on 486 PCs
Message-ID: <56063@nigel.ee.udel.edu>
Date: 12 Jun 91 04:43:19 GMT
Sender: mmdf@ee.udel.edu
Lines: 45

UK%"awb@ED.AC.UK"      "Alan W Black"  mentioned
>I'm not sure what the real differences are.  The 486 has a floating
>point processor as part of it.  I've never heard of a compiler that
>takes advantage of it (gcc doesn't seem to have any 486 extensions).  So
>I assume it is  basically 386 with better cache, pipelining and floating
>point.  Thus no real extensions to minix would have relevant.

Softwarewise 486 is similar to 386 so PC minix would have no problem with
486 but 486 is not just a 386 with better cache. It is a much improved 386.
486 has managed to implement most of the commonly used instructions in just
one cycle, so that it is slightly faster than SPARC RISC microprocessors ath
the same frequency of 25MHz.

In the IEEE MICRO FEB 1990
The geometric mean of the standard SPEC benchmark suite consisting of
gcc, espresso,eqnitott, the 486 has 13.0 versus 12.2 for SPARC and 19.6 for
MIPS.

Another interesting article is from Dr. Dobb's Journal , May 1991 titled
Coprocessor For a Coprocessor by Warren Davis and Kan Yabumoto.
The benchmark to calculate a fractal image is:

80386/80387              97
80486                    23
34020/34082              18
34082                     4

As you can see, 80486 is about 5 times faster than 80386 at the same frequency
Our experiece working with ORCAD PCB II which does not use a co-processor also
shows that 486 is about 5 times faster when doing routing optimisation.

Surprisingly, I find that the Sun Sparc Station 1, even without windows,
at 25 Mhz is so slow at screen updates compared to Minix on my 386/25 without
cache with  super VGA display.

Minix is even faster than DOS. The Berkeley Unix Sys 4.1.1 is such a burden
to the system that it slows down everything. Minix is not only for learning
but also for serious users who wants work done quickly. Its smallness makes
understanding it easier in case of any possible problems.

Even if BSD with MACH were free(or cheaper), there is still a place for Minix.
However it would be a  pity to lose people such as awb from the Minix group.

Othman Ahmad, School of EEE, NTU, Singapore 2263
E-mail:EOAHMAD@NTIVAX.BITNET