Tiger MP motherboard in rack

[Robert G. Brown]

On Tue, 19 Mar 2002 Wolfgang.Dobler at kis.uni-freiburg.de wrote:

> Our institute is planning to buy a 6-8 node Dual AMD (1800+MP) cluster,
> either as towers or in a rack.
>   One vendor suggested Tyan Tiger MP motherboards for the tower variant but
> the much more expensive Tyan Thunder K2 S2462NG for the rack cluster,
> while another vendor says we can use the same motherboard (Tiger MP) in
> both cases.
> 
> Can anybody give advice on whether it is a good idea or not to use the
> Tiger MP motherboard in a 2-unit rack? Are there thermal problems; would
> we need special ventilation?
> 
> Any help is appreciated,
> 
> W o l f g a n g
> 

You can use the tiger MPs (either 2460 or 2466) in a 2U rack.  You can
even find vendors on this very list that would be happy enough to sell
you tiger nodes in a 1U rack.

Issues with the racks that you should consider carefully are:

  a) Power.  The 1U or 2U cases need an AMD-certified power supply in a
conservative design (i.e. one you do NOT want to have to mess with
because of slightly inadequate power or some other design weakness).
Only some cases have this or can be fitted with this.

  b) Space.  Curiously, all motherboards (even "ATX" motherboards) are
not the same size -- they can vary by an inch or so in width or depth.
This matters.  Make sure that your cases can physically hold the Tigers.

  c) Fans and cooling.  The systems are kept cool by i) having the
ambient air in the room kept cool enough to efficiently remove the heat
generated by the CPUs and ii) having fans and airflow patterns that
deliver that cool air from outside the case to the hot components where
it can cool them, and then exhausting it into the ambient air to be
recooled by the room A/C.

Cases therefore need to have both ENOUGH fans to move air through the
cases and fans in the RIGHT PLACES to move that cool air over the hot
spots.  The CPUs themselves and any other "hot" components need
heatsinks and fans to further facilitate the exchange of heat.

  d) Peripheral support.  Cases may or may not need: riser(s) for 1-3
PCI cards (e.g. a video card, networking cards), a floppy, one or more
hard drives, a CD-ROM drive, a sound card to help you while away those
hours listening to loud music instead of 40 decibels of fan noise.

The tiger comes with a serial console in the bios and (2466) onboard PXE
bootable 100BT; you can design a diskless, floppyless, videoless,
riserless, 1U node that is basically motherboard, CPUs, and memory and
in all probability get it to run (or you could add just a single hard
disk to facilitate a local instead of network boot).  Or you might NEED
(just) 64/66 GbE, and could manage a 1U box with a single slot riser.

Or you might want 2U cases because they are a bit more conservative
design -- it is easier to fit everything in (including lots of
peripherals should you need them, cooling is easier and probably more
robust and reliable, and you still get a lot of CPUs in a single rack.

Hope this helps.  We've been getting Tigers built locally into 2U cases
our vendor gets from Anova (anova.com).  Anova's cases are very
reasonably designed and a decent price, but Anova has not been "perfect"
in things like timely delivery and returning phone calls from our system
vendor.  Neither have they been terrible -- but we're leaning on them to
get better and more reliable delivery and more responsive service and if
we don't get it on the next cluster purchase we'll likely change
vendors.  Anova would be happy to build the nodes and sell you nodes
instead of cases if that is how you prefer to proceed, but I like having
a local vendor to bang on when there is trouble -- delays in case
delivery is annoying but not generally critical, so dealing with a
California company is workable.  Delays in getting a down system repaird
may well be critical and you do NOT want a vendor that might take a week
to return a phone call.

I'm sure some other case vendors or turnkey systems builders on the list
will contact you directly given your solicitation above so you should
end up with a decent choice.  Hopefully you'll be able to converse with
them intelligently on the basis of the list of features above.

(List experts -- did I forget anything?  Power, cooling, space,
peripherals -- color?  cost?  case strength? nifty logos???:-)

   rgb

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu