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At 08:54 AM 11/10/2005, Andrew Piskorski wrote:<br>
<blockquote type=cite class=cite cite="">On Thu, Nov 10, 2005 at
05:35:03AM -0800, Jim Lux wrote:<br><br>
> However, lots of people have successfully built clusters from stacks
of <br>
> mobos. I think the biggest one (in terms of # of nodes) is the
one with a <br>
> dozen or so Via mini-ATX boards. I don't know that I've seen
any bare <br>
> bones clusters with more than 20 nodes.<br><br>
Oh, I know of at least 3 bare-board clusters much larger than that<br>
(and some smaller):<br>
</blockquote><br>
Excellent examples.. (what comes from making an off the cuff comment
before having my first cup of coffee in the morning)..<br><br>
<blockquote type=cite class=cite cite="">
<a href="http://jessen.ch/ammonite/" eudora="autourl">http://jessen.ch/ammonite/</a></blockquote><br>
Telling comment:<br><br>
"Perhaps the most helpful thing I could say is to urge you to
consider building a conventional cluster (shelves of COTS midtower cases
or racks of 1U pizza boxes) instead of something like ammonite. The
ammonite design has some advantages (high cpu density, better ventilation
and lower delta-T, for example), but designing and building it was a
colossal time sink. ... <br>
There were many little things that had to be custom made or modified, no
one of which was a big deal, but all of which together were a very big
deal. " (ellipses mine, JL)<br><br>
<br><br>
<blockquote type=cite class=cite cite="">
<a href="http://joule.bu.edu/~hazen/LinuxCluster/" eudora="autourl">http://joule.bu.edu/~hazen/LinuxCluster/</a></blockquote><br><br>
"Instead of a flat plate we use a custom-made aluminum box with
punched holes and welded corners made by a local sheet-metal house.
..."<br>
Dividing out their $4500 hardware cost, they spent just under $100/mobo
for packaging (their box was probably about half that). Note well,
they don't mention labor costs.. If you go custom box, you want to look
closely at boxes designed for mass production: sliding Tab A into Slot B
is a heck of a lot faster than fumbling for 6-32 screws.<br><br>
<blockquote type=cite class=cite cite="">
<a href="http://krone.physik.unizh.ch/~stadel/zBox/" eudora="autourl">http://krone.physik.unizh.ch/~stadel/zBox/</a></blockquote><br>
"<br>
We greatly acknowledge the aid of the
<a href="http://www.physik.unizh.ch/groups/werkstatt/">Physics Mechanical
Workshop</a> at the University of Zurich for: 1) turning the
"napkin-sketch" into a proper CAD/CAM design of the machine; 2)
providing numerous suggestions which improved the detailed design; 3)
providing a gigantic room for the construction of the boards; 4) and,
well, building the thing! <br>
"<br><br>
---<br>
In any case, ALL of these bigger systems had fairly custom designed
(read: not cheap) packaging hardware. They are pretty nifty
looking. <br><br>
<br>
They also raise some "serviceability" questions too...<br>
<br>
Jim</body>
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