high physical density cluster design -structural...

[David Grant]

This has been an interesting thread, but I do have a concern about
appropriate cooling  with "homegrown" 1U chassis.  Yes, you can build a box
the will physically support the hardware in a 1U form factor.  My concern
would be long term, and not so long term heat related failures on CPU's
and/or disk drives.....

just my .02


David A. Grant,  V.P. Cluster Technologies
GSH Intelligent Integrated Systems
95 Fairmount St. Fitchburg Ma 01450
Phone 603.898.9717       Fax 603.898.9719
Email: davidg at gshiis.com      Web: www.gshiis.com
"Providing High Performance Computing Solutions for Over a Decade"
----- Original Message -----
From: "Velocet" <mathboy at velocet.ca>
To: "Jim Lux" <James.P.Lux at jpl.nasa.gov>; <rutile at fixy.org>;
<bcrl at kvack.org>
Cc: <beowulf at beowulf.org>
Sent: Tuesday, March 06, 2001 2:49 PM
Subject: Re: high physical density cluster design -structural...


> On Tue, Mar 06, 2001 at 11:23:37AM -0800, Jim Lux's all...
> > Rather than the copper pipe and fittings (which isn't very structural,
and
> > will be a pretty significant problem as it gets bigger), you might want
to
> > look at some alternatives:
>
> Ya, were convening with a few people who've done some work with metal
> as well as piping this week to go over a few other cheap options. The
> cluster will be 48 to 64 nodes depending on pricing of other materials,
> network switches, etc. 48 nodes will be 2 stacks of 24, and at 1U per,
> thats only 3.5' tall. So we dont need something thats bombproof,
> just sturdy.
>
> > 1) UniStrut (available in aluminum and in galv steel) is much stronger,
has
> > nice 90 degree connectors, etc.  There are a variety of similar products
> > made from aluminum extrusions of one kind or another with longitudinal
slots
> > that make very nice rigid boxes. You assemble it with captive nuts and
> > bolts. The best thing about these products is that they are rectangular,
not
> > round, which makes attaching stuff much easier.
>
> Hmm, this stuff looks really great - and they seem to be somewhat local
> to me. :) Looks like it might not be that cheap however, even if it is
> 'cheap' for industrial applications. Wonder if I can find prices online
> somewhere here...
>
> > 2) Speedrail - a brand of cast aluminum fittings that works with
aluminum
> > tubing to make structures, etc. (and hand and safety railings...)
There
> > are other brands, as well.  There are versions for 2" and 1" tubing, at
> > least.  The tubing fits into the socket on the fitting, and you tighten
set
> > screws to hold it together.  (Or you can epoxy it....).  For a given $$,
the
> > aluminum tubing will be much stronger and more rigid than the copper
tubing.
> >
> >
> > As far as design guidelines go,  a 0.6 g side load, or so, would be an
> > appropriate number.  For instance, you should build it strong enough so
that
> > you can (gently) tip it over on it's side and not have it fall apart
during
> > the move.  In even a small earthquake, poorly braced sheet metal racks
> > loaded with many pounds of equipment just crumple.  Especially on less
> > expensive racking, a lot of the strength depends on the sides not
buckling,
> > and once it bends even a little bit, it just caves in.
> >
> > After all, some day, you WILL have to move the rack a bit, even if only
a
> > few feet to let them take up the tile underneath it.
>
> True. I dont have a scale, but the board with CPU and ram is about 1.5 or
> 2lbs, and the power supply is 2-3lbs. That adds up with 48 or 64 odd
> boards. (Need to figure out if I am going to double up the mainboards
> per powersupply, would save alot of weight).
>
> Thanks for the pointers!
>
> /kc
>
> >
> > >> >
> > >> > Problem 1
> > >> > """""""""
> > >> > The problem is in the diagram above, the upside down board has
another
> > >> board
> > >> > .5" above it - are these two boards going to leak RF like mad and
> > >> interefere
> > >> > with eachothers' operations? I assume there's not much to do there
but
> > to
> > >> put
> > >> > a layer of grounded (to the cabinet) metal in between.  This will
drive
> > up
> > >> the
> > >> > cabinet construction costs. I'd rather avoid this if possible.
> > >> >
> > >> > Our original construction was going to be copper pipe and
plexiglass
> > >> sheeting,
> > >> > but we're not sure that this will be viable for something that
could be
> > >> rather
> > >> > tall in our future revisions of our model. Then again, copper pipe
can
> > be
> > >> > bolted to our (cement) ceiling and floor for support.
> > >> >
> >
> >
>
> --
> Ken Chase, math at velocet.ca  *  Velocet Communications Inc.  *  Toronto,
CANADA
>
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