[Beowulf] A Cluster of Motherboard.

[Jim Lux]

At 08:54 AM 11/10/2005, Andrew Piskorski wrote:
>On Thu, Nov 10, 2005 at 05:35:03AM -0800, Jim Lux wrote:
>
> > However, lots of people have successfully built clusters from stacks of
> > mobos.  I think the biggest one (in terms of # of nodes) is the one with a
> > dozen or so Via mini-ATX boards.  I don't know that I've seen any bare
> > bones clusters with more than 20 nodes.
>
>Oh, I know of at least 3 bare-board clusters much larger than that
>(and some smaller):

Excellent examples.. (what comes from making an off the cuff comment before 
having my first cup of coffee in the morning)..

>   http://jessen.ch/ammonite/

Telling comment:

"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. ...
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)



>   http://joule.bu.edu/~hazen/LinuxCluster/


"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. ..."
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.

>   http://krone.physik.unizh.ch/~stadel/zBox/

"
We greatly acknowledge the aid of the 
<http://www.physik.unizh.ch/groups/werkstatt/>Physics Mechanical Workshop 
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!
"

---
In any case, ALL of these bigger systems had fairly custom designed (read: 
not cheap) packaging hardware.  They are pretty nifty looking.


They also raise some "serviceability" questions too...

Jim 
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