Beowulf Cluster

[Junio1]

I am trying to set up a Beowulf Cluster from a bunch of old PII 266 computers. Instead of just stacking the old computers, I would like to take only the MB, NIC (and HD if necessary) and stack them a few inches apart in a separate rack that I will make myself. There are only two 15amp circuits in the room, therefore I must conserve power. My question is this: Can you run more that one MB on one 300 watt power supply (assuming of course that I splice on more ATX power connectors)? If so, how do I calculate how many? Have any of you done anything like this and where would I go for more information. Thanks!

 

[DeschutesCore]

IMO, splitting the ATX rails is potentially dangerous on several fronts.

First off, cutting the power in half under load leaves you at 150 watts, enough in a lot of circumstances, but not enough in others. Also, as the boards are switched on a and off, you're gettting an awful lot of spiking per switch, mobo's are just too sensative to begin with.

Lastly, you'd be putting too much load on the rails. I would look at using mATX supplies instead.

If this was possible (and acceptable) dual board boxes would come with this kind of supply, and I have yet to see one.

DC

* Please note, I am not an electrical engineer. I am merely a systems builder that has worked on a number of projects involving power, basic custom circuits, and several custom cases with dual boards (two mobo's, one case). This is my opinion only.

 

[unclebabar]

I'm not an EE either, but since a P2-266 has a max power consumption of < 10 W, it would seem you'd be able to run at least 2 on 300 W. You'd have to run the numbers yourself, making sure than you have enough amps on each rail. I don't know about the spiking.

> If this was possible (and acceptable) dual board boxes would come with this kind of supply, and I have yet to see one

wouldn't it be cheaper (if it were possible and acceptable) just to have a Y-cable the splits the motherboard connector? I've never seen a dual motherboard box myself, much less a dual board PS.

If you burn your house down, my name is Geraldo and I live in a box.

 

[capybara]

ok, 2 x 15A = 30A X .8 = 24A usable X 110 vac = 2640 watts.
2640 w - 150 w for a monitor - 75 w for lighting= 2415 w.
if each board/hard drive uses 200 w, that allows 12 boardswithharddrives.
=================================================
BUT.....ac power is just the start. Beowulf clusters arent easy.....i would say they are closer to
being "an awesome accomplishment." The teacher of my LAMP class went to
a clustering class, and he said "not easy."

 

[Armitage]

Beowulf clusters arent easy.....i would say they are closer to
being "an awesome accomplishment." The teacher of my LAMP class went to
a clustering class, and he said "not easy."

Sure they are
Depends on how big & complex you need it, but a basic cluster is pretty simple.

FWIW, I wouldn't muck around with the power though. Just stack em in the corner.

As far as only having 2 15 amp circuits ... that's probably enough for at least 6 or 8 systems of the class you're considering, probably more. I have 4 systems of various vintage, plus alot of other junk (including a freezer!) on a single 15A circuit. It never tripped until I had the air compressor & radial arm saw on the same circuit this weekend! Just keep plugging them in until you trip the breaker. Then back off by a box or 2! I don't think you'll really save anything on power by splitting a power supply across 2 MB. The MB are going to draw the same power they always did.

 

[capybara]

Originally posted by: ergeorge

Beowulf clusters arent easy.....i would say they are closer to
being "an awesome accomplishment." The teacher of my LAMP class went to
a clustering class, and he said "not easy."

Sure they are
Depends on how big & complex you need it, but a basic cluster is pretty simple.

ergeorge: what distro did you use? the scyllyd beowulf available from
www.cheapbytes.com ? if you know a distro that makes it easy
(or easier) im gonna try it too!

 

[Armitage]

Originally posted by: capybara

Originally posted by: ergeorge

Beowulf clusters arent easy.....i would say they are closer to
being "an awesome accomplishment." The teacher of my LAMP class went to
a clustering class, and he said "not easy."

Sure they are
Depends on how big & complex you need it, but a basic cluster is pretty simple.

ergeorge: what distro did you use? the scyllyd beowulf available from
www.cheapbytes.com ? if you know a distro that makes it easy
(or easier) im gonna try it too!

For a run-of-the-mill cluster such as you're likely to build as a hobby, I don't think the distro is important. Of the clusters I have access to right now, one runs Suse, another RedHat 7.2, and the biggest one runs FREE BSD. My earliest experience in distributed computing was on Solaris. PVM & MPI will run on pretty much any *nix, same goes for most of the configuration and management tools.

So I'd pick whichever you're more comfortable with (or happen to have on hand).

I believe there is a fairly good Beowulf HOWTO. Check out Linuxdoc!
good luck