laptop cooling ideas?

Mon Aug 9 17:30:16 PDT 2004

>Date: Mon, 9 Aug 2004 17:05:15 -0700 (PDT)
>From: "Michael T. Halligan" <michael at halligan.org>
>To: baylisa at baylisa.org
>Subject: laptop cooling ideas?
>Sender: owner-baylisa at baylisa.org

>I just got a powerbook 17", and though I've fallen in love with it,
>I've also noticed the tremendous amount of heat it seems to shoot
>down. In the coming winter months, I'm sure I'll learn to love this
>feature, but right now it makes me nervous.

I thought you spent enough time in San Francisco that it woulld be
*summer* that you'd most appreciate that "feature."  :-}

>The first idea I've come up with is to buy a marble slab.. While this
>will be rather useless for placing upon my lap, or carrying, it should
>suck in the heat pretty well, since marble's a great heat sink. As a
>base to put the laptop on when it's on a desk, laptop stool, a
>chair/bed/pillow, it should work well (though be slightly cumbersome).

Well, actually marble isn't as good as, say, solid copper.  But you
still need dump the waste heat from the marble, copper, or whatever.
[/me envisions chilled water circulating between heavy copper plates...
that's what I get for spending so many formative years around IBM
mainframes....]  Have a pair of the artifacts (whatever they are), and
put the one not in active duty in a place where the waste heat could be
dumped?

>Beyond a big piece of rock, does anybody have any better ideas for
>cooling laptops, that are preferably quiet?

In all seriousness:

* My laptop gets pretty warm, especially when it's working on the 2nd
  "make -j6 buildworld" of the day.  I tend to set it atop an atlas when
  it's on my lap.

* About 2 weeks ago, it started showing signs of thermal stress (as did
  its predecessor, a couple of years ago):  it would get to some CPU-
  intensive activity and suddenly shut itself off.

  I found this disconcerting.

* Since I had the service diagrams, and had already taken apart the
  previous machine (which was made by the same folks, and was
  sufficiently similar to my current one that the peripherals and
  batteries were interchangeable), and since the current one was
  no longer in warranty, and the probability that I could afford
  to pay to have it fixed or replaced was no greater than epsilon,
  I opened it up.

  The (intake) fan had become somewhat occluded, so I cleaned that out.
  Of course, the only way I could tell was by popping the heat sink,
  which destroyed the thermal tape that connected the heat sink to the
  metal plate atop the CPU.  The usual "thermal grease" was not up to
  the task -- it needs to be a very thin layer, while the "thermal tape"
  was more like a foam with a substrate, and was thus relatively thick.

  I tried some "thermal tape" from Fry's; it wasn't think enough either.
  So I tried 2 layers, laid front-to-back.  That didn't seem to work,
  either, but then I let the machine just sit, powered off, for
  overnight and the following day.  Afterward, I powered it up, and it
  seemed OK, so I left it running while I went to work.  Once there, I
  fired up a task to ping the laptop every 5 minutes or so ... and ut
  stayed up all day.  Anyway:  the 2 layers of tape seemed to do OK.

  NOTE:  I am *not* recommending such surgery, especially for a working
  machine.  Don't blame me if you destroy a machine or void your
  warranty.  But while the laptop is powered off, you might try checking
  to see if the fan is getting occluded.

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
Evidence of curmudgeonliness:  becoming irritated with the usage of the
word "speed" in contexts referring to quantification of network
performance, as opposed to "bandwidth" or "latency."