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From: michaelv@MindBender.HeadCandy.com (Michael L. VanLoon)
Newsgroups: comp.sys.ibm.pc.hardware.chips,comp.sys.ibm.pc.hardware.systems,comp.os.linux.hardware,comp.unix.bsd.freebsd.misc
Subject: Re: Dual Pentium MotherBoard.
Followup-To: comp.sys.ibm.pc.hardware.chips,comp.sys.ibm.pc.hardware.systems,comp.os.linux.hardware,comp.unix.bsd.freebsd.misc
Date: 03 Oct 1995 03:37:23 GMT
Organization: HeadCandy Associates... Sweets for the lobes.
Lines: 51
Message-ID: <MICHAELV.95Oct2203731@MindBender.HeadCandy.com>
References: <44735j$7qo@kappa.usc.edu> <DFHG2v.7Mw@ritz.mordor.com>
<4491rp$gb0@mozo.cc.purdue.edu> <44lr4s$g94@wn1.sci.kun.nl>
<44p0vn$644@News1.mcs.net>
NNTP-Posting-Host: mindbender.seanet.com
In-reply-to: hendryj@Mercury.mcs.com's message of 2 Oct 1995 15:37:27 GMT
Xref: euryale.cc.adfa.oz.au comp.sys.ibm.pc.hardware.chips:35001 comp.sys.ibm.pc.hardware.systems:20765 comp.os.linux.hardware:17685 comp.unix.bsd.freebsd.misc:7029
In article <44p0vn$644@News1.mcs.net> hendryj@Mercury.mcs.com (Jonathan W. Hendry) writes:
Mark van Hoeij (hoeij@sci.kun.nl) wrote:
: In <4491rp$gb0@mozo.cc.purdue.edu> lin1974@expert.cc.purdue.edu (Chien-hung Lin) writes:
: >What systems or OS or programs would take advantage of the extra
: >CPU?
: One of the workstations here has 4 CPU's.
: If you run 1 computation on it the machine is not faster than the other
: workstations. However, if you run 4 computations on it then all 4 get
: 100% CPU time instead of 25%.
: This is useful on systems with lots of users who run CPU intensive apps.
Hmm. Programming question. Under Windows NT, on a multi-processor
box, is it possible to run copies of an application on each processor?
Is is possible to specify which processor an application should run on?
Yes. Yes.
If I wrote a Photoshop plug-in filter, could I have it spawn off little
daemon-like filtering engines, one on each available processor?
The Right Thing To Do (tm) on NT is to spawn a separate THREAD for
each thing in a single process. But, yes, your concept would work
fine.
Just curious if the capability is there, or if processors are handed out
by the OS.
Yes. If your process is given a set of processors to run on (a
process affinity mask or something like that), you can specify for each
thread or spawned process a subset of those processors you want it to
run on, but you can't specify more than you've been given. For
example, your process is given a mask that lets it run on processor
1 and 2, in a four-processor system. It can't twiddle its mask to let
it run on processor 3, but it could limit a spawned thread or process
such that it could ONLY run on processor 1 or 2.
There is quite a bit published about this, actually, so I'm not going
to get terribly detailed. You should look at the books from Microsoft
Press if you're really interested in this.
--
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Michael L. VanLoon michaelv@HeadCandy.com
--< Free your mind and your machine -- NetBSD free un*x >--
NetBSD working ports: 386+PC, Mac 68k, Amiga, HP300, Sun3, Sun4,
DEC PMAX (MIPS), DEC Alpha, PC532
NetBSD ports in progress: VAX, Atari 68k, others...
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