Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!aplcen!boingo.med.jhu.edu!haven.umd.edu!mimsy!mojo!eng.umd.edu!tgoose
From: tgoose@eng.umd.edu (Jason Garms)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Unix on 486 Machines
Message-ID: <1991Jun12.002349.19724@eng.umd.edu>
Date: 12 Jun 91 00:23:49 GMT
References: <9106110417.AA06408@w20-575-117.MIT.EDU>
Sender: news@eng.umd.edu (C-News)
Reply-To: tgoose@eng.umd.edu (Jason Garms)
Organization: College of Engineering, Maryversity of Uniland, College Park
Lines: 42

In article <9106110417.AA06408@w20-575-117.MIT.EDU>, pshuang@ATHENA.MIT.EDU writes:
> In article <44390@netnews.upenn.edu> jer@pender.ee.upenn.edu (Joel
> Ratsaby) writes:
> 
>  > Is the architecture of 486 ISA  (Not EISA) machine fit for
>  > Unix or is the 32 bit capability of the 486 is masked by the
>  > ISA architecture ?
>  > 
>  > If I use DOS 5.0 can I do multitasking (without Windows package)
>  > and is the 32 bit capability of the 486 masked by DOS ?
> 
> 486 ISA machines are quite fit for UNIX, as are 386 ISA machines.  You
> won't get the same kind of snappy performance as the mid to high-end
> workstations, but it will be acceptable, especially if you spend a fair
> amount of money to insure that the machine is equipped with a very fast
> and large disk drive and a speedy display adaptor board which can
> support a high resolution screen and possibly has a graphics coprocessor
> on it.  The bus does not seem to be as huge an issue as IBM would have
> had you believe with their push for MicroChannel architecture, according
> to PC Magazine tests about a year back, when they concluded that for
> most setups and users and applications, ISA vs. EISA vs. MicroChannel
> made little difference to real-world throughput.  In any case, ISA's
> 16-bit bottleneck applies only to I/O and does not affect the 32-bit
> processing speed of the i486 CPU, unless you are supplying memory via a
> expansion board on the bus, which would be plain silly.

[Stuff deleted]

> Singing off,
> UNIX:/etc/ping instantiated (Ping Huang).

There are two major differences in running UNIX on an ISA and an EISA
bus.  The first is that on an ISA bus, expansion cards cannot address
an memory you may have over 16MB.  For some people this may not be a
problem, for others it might.

The second thing is that EISA boards provides significantly better performance
in a network than ISA machines.  If you are looking to use it as a server,
then the EISA machine would be a much better choice.

Jason Garms
tgoose@eng.umd.edu