Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!jato!mars!kaleb
From: kaleb@mars.jpl.nasa.gov (Kaleb Keithley)
Newsgroups: comp.sys.ibm.pc
Subject: Re: 386 < -- > 386SX?
Message-ID: <2743@jato.Jpl.Nasa.Gov>
Date: 5 Feb 90 18:40:35 GMT
References: <3533@uceng.UC.EDU>
Sender: news@jato.Jpl.Nasa.Gov
Reply-To: kaleb@mars.UUCP (Kaleb Keithley)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Lines: 27

In article <3533@uceng.UC.EDU> schriste@uceng.UC.EDU (Steven V. Christensen) writes:
>I understand that a 386SX  has some of the functionality of a 80386.
>Will it run, for example, multi-tasking OS like Microport Unix?
>Will it run OS/2 ? What can a 386 do that a 386SX can't?
>
>Thanks for your patience with this, I'm sure, much rehashed subject.

You're right, it has been rehashed over and over again.... Maybe this topic
ought to go in the monthly "frequently asked questions" posting.

A 386SX is 100% compatible with a 386DX.  NO ifs, ands, or buts!  I run OS/2
and ESIX 5.3.2.C, as well as DOS on my 386SX.  An SX is just slower than DX
because it only has a 16 bit data path, versus the DX 32 bit data path.
Therefore, all 32 bit memory accesses on the SX require two reads instead of
one.

Incedentally, by comparison, my friends 20mhz DX with 32k cache gets a 22
from Norton's SI, while my 16mhz SX (no cache) gets a 17.  The DX scores about
6500 dhrystones, while the SX rates at 5500.  Under ESIX, the DX runs around
5500 dhrystones, while the SX gets about 4000.  Under ESIX with gnu cc 1.36
the SX gets up to 5500 dhrystones.  Haven't tried gnu on the DX yet.


Chewey, get us outta here!
                 
kaleb@mars.jpl.nasa.gov            Jet Propeller Labs
Kaleb Keithley