Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!udel!udccvax1!gilmore
From: gilmore@vax1.acs.udel.EDU (Scott Gilmore)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Tandon 486, DesqView, Landmark Speedbar question
Summary: Not so, says PC Magazine
Keywords: 486
Message-ID: <5092@udccvax1.acs.udel.EDU>
Date: 22 Nov 89 15:31:49 GMT
References: <8@tandon.UUCP> <2554PICHER@MAINE> <1989Nov21.220611.4804@world.std.com>
Organization: University of Delaware
Lines: 29

In article <1989Nov21.220611.4804@world.std.com> madd@world.std.com (jim frost) writes:
>PICHER@MAINE.BITNET (Michael W. Picher) writes:
>>Now, suppose you run in a Desqview window... You are
>>running the processor in the protected mode and it will run faster
>
>You are mistaken; protected mode will slow the processor down, as it
>must do access checking.  ...
>jim frost
>software tool & die
>madd@std.com

Not so, says the latest issue of PC Magazine.  According to PC, the new
optimizations in the 486 design mostly affect protected
mode operation.  They found that the projected speedup factor of 2 or more
from a 386-33 to a 486-25 was not realized for DOS applications, where they
found only a speedup of roughly 10%.  Some of the 486-based machine
manufacturers (such as ALR and HP) claim that the projected speedup becomes
reality when running in protected mode.  PC Mag. did not test the machines
in protected mode themselves.

I suppose the best test would be to benchmark true 386 32bit applications on
both processors.  Anyone with the hardware and software to do it?

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Scott Gilmore                                               Research Assistant
University of Delaware                              gilmore@vax1.acs.udel.edu
Center for Composite Materials                      gilmore@oscar.ccm.udel.edu
Dept. of Mechanical Engineering                     gilmore@minnie.me.udel.edu
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