From: kroe AT sbcs DOT sunysb DOT edu (KiYun Roe)
Date: Thu, 28 May 92 21:47:34 EDT
To: JMILLER AT CHESS DOT EISC DOT UTOLEDO DOT edu, djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: How fast?? part 2
Status: O

The likelihood that you experienced the same problem I did is very
small, but I will tell you about it anyway.  I began experiencing
unusually slow speed with djgpp-compiled programs when I recently
switched to QEMM.  I had turned off the built-in ROM shadowing on my
machine and let QEMM recover the shadow RAM for general use.  My BIOS
also lets me control caching on portions of the address space, and the
default is to turn off caching for some of the regions in the A000-FFFF
area.  It turns out that these must be physical addresses, because I
discovered after a bit of work that the slowdown was occurring when my
program happened to be loaded in the shadow RAM, most of which was
uncached.  The solution was to go into the BIOS setup and turn on
caching for all the memory regions.  So my suggestion to you is to
fiddle with some of your BIOS settings and see if they do anything for
your execution speed.