Path: utzoo!utgpu!watserv1!watmath!att!occrsh!uokmax!munnari.oz.au!samsung!umich!mailrus!ncar!boulder!snoopy!wallwey
From: wallwey@snoopy.Colorado.EDU (WALLWEY DEAN WILLIAM)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Why use MS-window ?
Message-ID: <21855@boulder.Colorado.EDU>
Date: 4 Jun 90 18:23:46 GMT
References: <404@newave.UUCP> <10509@ingr.com> <54985@microsoft.UUCP> <1990Jun4.144158.22800@sj.ate.slb.com>
Sender: news@boulder.Colorado.EDU
Reply-To: wallwey@snoopy.Colorado.EDU (WALLWEY DEAN WILLIAM)
Organization: University of Colorado, boulder
Lines: 43

In article <1990Jun4.144158.22800@sj.ate.slb.com> poffen@sj.ate.slb.com (Russ Poffenberger) writes:
>Whoa! hold on here! Unless you have a seperate processor for each process,
>there is still going to be degradation when more than one task is running.
>As long as there is only one CPU to do all the work, then multiple tasks will
>each run slower than they would if they were run by themselves. 
>
>Plain and simple, no ifs, ands, or buts.
>
>A good multitasking OS can reduce the overhead of multitasking since it was
>desgined to do that, as opposed to a more band-aid approach like windows
>takes, but the performance hit is still there.
>
>
>Russ Poffenberger               DOMAIN: poffen@sj.ate.slb.com
>Schlumberger Technologies       UUCP:   {uunet,decwrl,amdahl}!sjsca4!poffen
>1601 Technology Drive		CIS:	72401,276
>San Jose, Ca. 95110             (408)437-5254

There is not neccessarily a large hit at all if the OS is designed right. 
The previous example about pagemaker is very good.  Granted a proccessor can
only do x amount in x time but how you distribute that HIT (example-printing)
is very important.  In
PageMaker for OS/2, when you print something, it creates a low priority
thread to do it.  That way you can go on doing your work as usuall.
While the computer is waiting for you to type more, it can be 'printing'
in the background, but at soon as you hit a key, the main pagemaker
thread comes into action.  After a couple of (relatively) 100s
instructions when the kerstroke is proccessed, page maker can return
back to the print thread which requires (relatively) 100s of thousands
of instructions. The small time required to proccess the keystroke is
practically nill in light of how much work must be done to printout a
page. So your page takes an aditional 3 seconds to printout--almost nothing
in light of how long it takes to print out Pagemaker docs.  On the other
hand if it takes 1/2 second after every keystroke to get a responce, you
can obviously see the degration.  This is what makes OS/2 so great and
Windows so bad!  Even though in theory there is the same amount of
degration on both, for practical purposes there is no degration of OS/2
in certain cases.  EACH TASK DOES NOT RUN SLOWER, ONLY SOME DO, when you
increase the number of tasks! To find out more on the subject, see
Charles Petzold's article in one of the latest PC Magazines.
(This is actually where I got the Pagemaker example!)

	-Dean Wallwey