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From: ernst_witter@eva.slu.se
Newsgroups: comp.windows.ms
Subject: Re: Severe performance degradation with 386 enhanced mode, any tips?
Message-ID: <7311.279bff79@eva.slu.se>
Date: 22 Jan 91 08:01:45 GMT
References: <1991Jan16.224240.14201@news.iastate.edu> <1991Jan17.234310.6393@mintaka.lcs.mit.edu> <6219@exodus.Eng.Sun.COM>
Organization: SLU, Swedish university of agricultural sciences
Lines: 44

There has been some discussion about the degradation of performance
(here meant that applications run slower) when running Windows in 386Enh
mode, compared with standard mode, or when running the DOS applications
outside of Windows. I have 386SX (16Mhz) with 5Mb total memeory and have
been running Windows for about 6 months. I mainly use non-Windows applications
and have also observed the above mentioned degradation of performance. 
Using the system performance indices which I have I've tried to locate what
is causing this slowing down of the machine. Not surprisongly the outcome
is somewhat dependent on which test you run. I've run Norton index (v4.5),
Landmark CPU test v0.99, and MicroSystems HSPEED prgram. The latter is special
in that it only tests block writes to memory and registers and simple
arithematic performance by these two (is not affected by presence of co-proc).
Running my machine (0 Wait State) without any management of its extended 
memory gives the following:
	Norton:	15.6
	Landmark: 21.0 Mhz (rel to AT)
	HSPEED: 783% (rel to IBM/PC)

Installing HIMEM.SYS reduces performance according to Landmark by 32% and
according to Norton by 4%. HSPEED gives same performance:
	Norton: 15.0
	Landmark: 14.3 Mhz
	HSPEED: 783% 
Further installing emm386.sys and/or smartdrv.sys has no further (other than
that caused by HIMEM) effect on system performance. It is interesting to note
here that simulating expanded memory in hardware/software with emm.sys supplied
with the machine does not affect system performance.

The next step was then to run these tests from Windows (exclusive, full screen,
no other programs loaded except program manager). Here it was only Landmark
which showed a further degradation of performance (8.0 Mhz) compared with
having only HIMEM installed.
The conclusion must therefore be that -for some programs at least- the
problem of Windows degrading performance in 386Enh is simply due to the 
need for HIMEM. Note however that as soon as you run a non-Windows application
not-exclusive things soon grind to a virtual halt, especially if you try
to display things in a window. As far as Windows use with non-windows
applications, it is a great task switcher but as for efficient multi-
tasking or trying to use the pasting between applications facilities it is
certainly not living up to its promise.

I would be interested to hear from anyone using QEMM with Win3.

Ernst Witter