Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!casbah.acns.nwu.edu!ftpbox!motsrd!motcid!koch
From: koch@motcid.UUCP (Clifton Koch)
Newsgroups: comp.sys.ibm.pc.hardware
Subject: Re: Why buy a DX over an SX?
Message-ID: <6981@navy22.UUCP>
Date: 25 Apr 91 16:03:30 GMT
References: <1991Apr21.203004.9909@unlv.edu>
Organization: Motorola Inc., Cellular Infrastructure Div., Arlington Heights, IL
Lines: 21

From article <1991Apr21.203004.9909@unlv.edu>, by whitney@reed.cs.unlv.edu (Lee Whitney):
-> In article <1991Apr12.162615.13529@holos0.uucp>, lbr@holos0.uucp (Len Reed) writes:
-> ) 
-> ) So what?  You're running *all* 16-bit software and you want to know
-> ) why having a a 32-bit data path doesn't buy you much?  Windows puts
-> ) the machine into proctected mode, but it doesn't use 32 bit mode.
-> ) 
-> Your statement is impratical and misleading.  First, the 386SX DOES have a        32 bit data path or else it would not be a 386!  It's bandwidth is only limited   across the bus, and since 90% of 386 buses are 16 bit (ISA), most DX systems would not realize a tremendous advantage over SX's when using 32-bit protected mode software.
-> 
-> A $200 cache may be worth a 25-30% performance increase, but the 5-10% increase of a DX over an SX with a 16 bit bus is probably not.

  The 386SX has an *internal* 32 bit bus.  Externally it's only 16 bit.

  You get more than a 5-10% increase.  The system memory where all your code you're running does not
reside on the crippled ISA bus.  It doesn't make much of difference when you're doing memory intensive
work on cards in the expansion slots (i.e. video).  The main reason I see for a DX over an SX is that
the DX's are available at higher clock speeds, especially now that the AMD 40 MHz versions are out.
-- 
-----------------------------------------------------------------------------

... [uunet | mcdchg | gatech]!motcid!koch