[Beowulf] A Cluster of Motherboard.

[Florent Calvayrac]

Robert G. Brown wrote:

>
> In this latter case, you can probably get by by taking sheets of steel
> or aluminum, drilling them out using the mounting holes of the
> motherboard as a template, and mounting the motherboards on them using
> the standard spacers and screws just LIKE a case.  

We used metal rails in our enclosure of 8 CPUs(about which I already posted
on that list, however I don't think that the student
website about it is still up) to mount the motherboards :  this way, no 
need for a
precise adjustment of the holes, only the rail spacing
has to be measured carefully. We just pierced a number of large
holes at the bottom of the case for vcntilation.

The cluster took us about three weeks of work to build
(thus the money saved on the cases was wasted here) but we learned
a number of things about cooling, and we now have a valuable
exhibit for lab visits and so on. The cluster has now been running
fine for two and a half years : the money saved on the cases allowed us 
to buy
 excellent fans and power supplies which is not necessarily the
case with cheap cases sold by assemblers. In a way the three weeks
of work have been compensated by the total absence of maintenance.


No ground loops problems at all ; we used a common rail to plug the
power supplies.





F.C.