From: waverheu@VUB.AC.BE (Verheulpen W.)
Newsgroups: bit.listserv.win3-l
Subject: re: Re[2]: Speed in Windows
Date: 16 Dec 92 15:33:26 GMT
Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU
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              Dec

In a posting Brent A. Waechter writes :
>
>
> >>>Why do you need Qemm ??? Windows wil start with about 300 Kb base
> >>>memory. And what is must worse Qemm eats 25% of your processor
> >>>performance, so who wants that ...!!
>
> >     QEMM gives me, with MANY device drivers loaded, around 612k before I
> >load Windows, under windows, it helps manage memory. It has its benefits.
> >
>
> I was having some problems receiving mail yesterday so I may have missed
> something in this discussion ...But where do you get your information on
> QEMM eating 25% of your processor performance?  Windows will start with
> less RAM but still requires some form of XMS memory manager (i.e.
> HIMEM.SYS.)  QEMM is this XMS memory manager as well as a UMB memory
> enabler (I think those are the correct terms.)  I have several boot
> configurations on my 486/25 system, one of which does NOT load QEMM.  I am
> fairly sensative to overall system performance and would dare say that a
> 25% hit on CPU performance would cause a noticable degradation in overall
> system performance.  I simply do not see that occur.
>
> ==================================================
> /  Brent A. Waechter                             /
> /  Rockwell International                        /
> /  Info. Systems Center                          /
> /  Internet:BAWAECHT@CORPSB.REMNET.ROCKWELL.COM  /
> /  (310) 797-2494                                /
> ==================================================
>
I want to recall a discussion of the same kind going on a very long
time ago on this very same list.
The issue was the speed of windows under various XMS & UMB managers.
We have conducted a lot of tests with qemm versions 5.xx & 6.01 both
under win 3.0 & win3.1
From all that it is quite clear that qemm 'bottlenecks' the system speed
up to the mentionned 25%. Furthermore & depending more or less on the
type of video card used, qemm 'eats' up to 70% of your raw video speed.
Why it does so is not quite clear & a number of hypothese have been
put forward. Fact is that it does. If you do not believe it, just try
to load qemm & run a benchmark like checkit. Then set up yr system with
himem.sys & compare speeds. Yre in for a surprise. Using the 'stealth'
possibility with qemm makes speed even worse & mostly there is no reason
to use it. I suggest that you try out umb_drvr.sys to provide UMB's &
compare the speed of yr PC then with the qemm setup.
Furthermore there is basically no need to use qemm as an EMS manager
with windows. Windows has it's own one, so you can free up the EMS
page frame that qemm installs. Unless you might think you need it, but
after quite some years of use & experimenting it turns out that we don't
need it.
Maybe the degradation of cpu perf did not strike you but video speed
surely should !

--
====================================================================
Willy Verheulpen                            Systems Coordination
                   Institute for Molecular Biology
Brussels Free University                                 Belgium
I-------------------------------------I----------------------------I
I Bitnet :   waverheu@bbrbfu60.bitnet I Things tend to get worse   I
I Intern :   waverheu@vub.ac.be       I under pressure (Murphy)    I
I_____________________________________I____________________________I
Usual Disclaimer: No connection with any commercial product.
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Comments: Gated by NETNEWS@AUVM.AMERICAN.EDU