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From: slin@cory.Berkeley.EDU (Steven Philip Lin)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Slow diskdrive with DESKview
Message-ID: <17608@pasteur.Berkeley.EDU>
Date: 24 Sep 89 23:27:07 GMT
References: <170@sluga.UUCP> <688@fiver.UUCP>
Sender: news@pasteur.Berkeley.EDU
Reply-To: slin@cory.Berkeley.EDU.UUCP (Steven Philip Lin)
Organization: University of California, Berkeley
Lines: 28

In article <688@fiver.UUCP> palowoda@fiver.UUCP (Bob Palowoda) writes:
>From article <170@sluga.UUCP>, by joakimf@sluga.UUCP (Joakim Fredriksson):
>> 
>> 
>> 	I think I've seen something about this before. But at the time I 
>> 	didnt "need" the information. My experience is that when I'm running
>> 	DESKview my diskdrive seem to operate slower. . . .

In the back of the Desqview manual is a suggestion for improving the speed
of file operations under Desqview.  First, some background.
     The Desqview authors claim that file operations use DMA, but that
expanded memory isn't compatible with DMA.  As a result, all file operations
under Desqview must be performed using conventional memory.  Desqview is
normally set up with a 2k buffer of conventional memory for such file
operations.  This buffer, however, may sometimes be too small.  Now the
solution.
     A way to improve the performance of file operations is to increase the
size of this buffer.  In the setup program for Desqview there is an option
to change the DOS buffer for EMS.  The option is located under the performance
heading.  The authors suggest increasing this buffer in 2 or 3k increments,
though little is gained by increasing it beyond 30k.
     There is an exception to this suggestion.  If you have an 80386 machine
with QEMM-386 version 4.1 or later, set the DOS buffer for EMS to 0.
Apparently the 386 is able to get around the limitation of requiring 
conventional memory for DMA transfers.

All of this information was taken from the manuals of Desqview 386 v 1.0 (i.e.
Desqview v 2.25 and QEMM-386 v 4.2).