Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!ncar!gatech!psuvax1!psuvm!dsb100
From: DSB100@psuvm.psu.edu (David Barr)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: Is DOS 5.0 really so slooow!
Message-ID: <91174.112235DSB100@psuvm.psu.edu>
Date: 23 Jun 91 15:22:34 GMT
References: <1991Jun20.223605.18977@IRO.UMontreal.CA>
 <1991Jun23.034521.7819@galileo.cc.rochester.edu> <8043@spdcc.SPDCC.COM>
Organization: Penn State University
Lines: 22

In article <8043@spdcc.SPDCC.COM>, jin@spdcc.COM (Jerry Natowitz) says:

>In article <1991Jun23.034521.7819@galileo.cc.rochester.edu>
>gwni@troi.cc.rochester.edu (G. Wayne Nichols) writes:
>>My experience indicates that any use of HIMEM.SYS will dramatically
>>slow down the Landmark rating, if not your actual system.

>I have played around with various configurations and found that EMM386 seems
>to be the culprit - my apps are runjning in protected mode when I use it for
>upper memeory access.  I don't even have to do any devicehighs or loadhighs,
>just having emm386 noems is enough.  Maybe I'll try removing himem for laughs.

Yes, if you think about it, it is obvious.  EMS memory is _paged_ memory.
That means when an application requests memory that is not in the 64K page
frame, the page is swapped out, and another is brought in.  This is a
ludicrous system for managing memory, but for some stupid DOS programs,
this is required, even on a 386.  XMS is faster than EMS because it is
a direct access system.  If an application needs a memory value in XMS,
it merely addresses it and reads it.  I never use EMS unless I want to
slow my system down.  =)

--Dave