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Date: Sun, 27 May 2001 12:43:13 +0930
To: cygwin AT cygwin DOT com
From: Mike Fahlbusch <mcf AT cobweb DOT com DOT au>
Subject: Re: The heating on notebook
In-Reply-To: <20010526135021.A8207@redhat.com>
References: <4 DOT 3 DOT 1 DOT 2 DOT 20010526133449 DOT 020b43c8 AT pop DOT ma DOT ultranet DOT com>
 <Pine DOT GHP DOT 4 DOT 21 DOT 0105261333330 DOT 11462-100000 AT jfk DOT carmen DOT se>
 <4 DOT 3 DOT 1 DOT 2 DOT 20010526133449 DOT 020b43c8 AT pop DOT ma DOT ultranet DOT com>
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At 13:50 26-05-01 -0400, you wrote:
>On Sat, May 26, 2001 at 01:42:38PM -0400, Larry Hall (RFK Partners, Inc) 
>wrote:
> >At 07:43 AM 5/26/2001, Rastislav Galia wrote:
> >>The subject of the message might seem strange in this context. But ... I
> >>have bought notebook Toshiba Satellite ...(some numbers) with 600MHz
> >>Celeron inside. The OS installed is Win ME. There are no problems with the
> >>machine except when I try to run a Cygwin on it.
> >>Cygwin runs but machine starts to get really hot (I swear this is truth,
> >>although it seems funny). The built-in cooler starts working every now and
> >>then automatically (in case I don't run the cygwin it doesn't need to be
> >>run at all, maybe with exception of Ms Flight Sim 2000).
>
> >>Has anybody an explanation ? Is it a hardware problem or is it a side
> >>effect of Cygwin ?
>
> ><humor>
> >One day, Cygwin will be used for embedded applications.  That means it will
> >be the basis of many electronic household devices, including microwave and
> >conventional ovens.  In preparation for this, the Cygwin team has created a
> >small internal routine to cause machines to heat up.  Its a "proof of
> >concept" that will pave the way to Cygwin's bright embedded future.
> >Theoretically, its now possible to fry an egg or pop your favorite popcorn
> >on you laptop while running Cygwin.  Its a great feature and its bound to
> >cause quite a buzz!
> ></humor>
>
>Hmm.  You've stumbled onto part of our grand design.
>
>There is actually a slightly more sinister component as well.  Imagine a
>covert application where, when properly triggered, we'll be able to take
>out enemy agents who attempt to use CygWin.  If we could heat up the
>agent's computer to, say, 3000 degrees Fahrenheit we would be
>unstoppable.
>
>"Hmm, comrade, did the Cygwin setup install the latest version of XFree86
>on your laptop?"
>
>"I don't know, comrade.  I think it just put all of the downloaded files
>into one large tar file called 'Rosebud'.  You know how unstable that
>capitalist 'free software' can be.  Just let me do a patriotic 'ls' and
>I will tell you the answer to your query."
>
>FWOOWWSHH!!!
>
>"Gahhhhhhhhhhhhhhhhh!!!!!!!!!!"
>
>And, the world is safe for democracy once more.
>
>Unstable, my eye.  It's all part of a master plan...

<humour++>
KGB?  I didn't mention anything about the KGB.  I would have said your name 
was Indian (although of course this doesn't matter).

Comrades, with the collapse of the glorious United Socialist Soviet 
Republics, we can now reveal the technical wizardry behind the cygwin shell 
fusion bomb.

It's really quite simple, kamerade.  Given a capitalist computer with power 
save features (a laptop or even a modern desktop computer will do) and a 
cygwin shell program (bash will do nicely), any computer can be turned into 
a thermal explosive.

cygwin shell programs use up CPU cycles even when they're not doing 
anything (the shell is idle).  Normally this CPU power would be liberated 
to other hard working programs, but shell programs gobble all of the CPU 
resources they can get.  So instead of the CPU getting a rest when the 
programs are idle, it works hard all of the time.  This produces more heat 
in the CPU.  If you leave it running for several days, it gets hotter and 
hotter.  Thermal runaway occurs, the CPU fuses and explodes destroying the 
computer and everything in the area.  Why hasn't the whole world been 
destroyed by one of these fusion devices?  Because the explosion occurs in 
three dimensions, the energy density reduces by distance on an inverse cube 
basis.
</humour++>

To answer your question, it's a side effect of the cygwin bash shell.  It 
doesn't seem to release the unused part of a multi-tasking timeslice to 
windows, so cooler programs or power saving hardware don't get a chance to 
work.  It's only natural the CPU will heat up when you are actively using a 
program, but when you exit the cygwin program, the CPU will cool down again.

dasbedanya

-
Regards,
        Mike

Sig:
I'm not addicted to the Internet.  I only use it once a day, and I can stop 
whenever I want.



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