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At 08:43 PM 11/4/2005, oxylabtech@gmail.com wrote:<br>
<blockquote type=cite class=cite cite="">Hello<br>
<br>
It would like to know if is possible to make a cluster of
motherboards? I don't speaking in a cluster of PC's, but of motherboards.
Somebody already saw? If it is possible, Could someone help me?<br>
</blockquote><br>
Sure it's possible.<br>
Your problems are going to be power, cooling, and structures (assuming
you're not in an environment where people care about electrical codes, RF
interference, etc.)<br><br>
Most mobos are designed to be installed by themeselves in a case with
cooling running approximately across the board and with a fair amount of
clearance above the board. If you start stacking them close
together, you might find it trickier to cool (although, with enough high
power fans, anything is possible<grin>)<br><br>
Power supplies might be another problem. In a lot of computers, the
power supply is bigger than the mobo, since the PSes are all designed to
the standard ATX formfactor. You "might" be able to run
multiple boards off one power supply, but there are some traps for the
unwary:<br>
1) At low voltages (5V, 3.3V) and high currents (tens of Amp) there's
going to be significant voltage drop in the wire between mobo and
PS. With just one mobo, that's taken care of by a sense wire.
With two, it's a bit more complex.<br><br>
2) Sequencing and standby modes. You'll have to figure something
out.<br><br>
3) Structural. Eventually you'll have to change something. It
might seem elegant to just stack things on a long piece of threaded rod,
but if you have to get to the board in the middle of the stack, you're in
for a tedious project.<br><br>
4) Grounding. If you're hooking anything other than ethernet cables
(which are galvanically isolated) to them, and you have multiple boards
connected together by the ground planes (the threaded rod approach, for
instance) you might have a problem with ground loops, because you'll have
multiple return paths.<br><br>
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. Probably because
no "professional" user would ever trust such a thing, so you're
left with a hobby cluster by an individual, and when you get to a cash
outlay of thousands of dollars, things like allthread and cobbled
together power supplies lose their appeal.<br><br>
<br>
<blockquote type=cite class=cite cite=""><font face="arial" size=2>Thankx³<br><br>
--<br>
<br>
Fernando.<br>
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<x-sigsep><p></x-sigsep>
James Lux, P.E.<br>
Spacecraft Radio Frequency Subsystems Group<br>
Flight Communications Systems Section<br>
Jet Propulsion Laboratory, Mail Stop 161-213<br>
4800 Oak Grove Drive<br>
Pasadena CA 91109<br>
tel: (818)354-2075<br>
fax: (818)393-6875<br>
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