[Beowulf] Opteron cooling specifications?
hahn at physics.mcmaster.ca
Mon May 1 08:41:29 PDT 2006
> 50u racks are also available (I've seen them in colo facilities)...
> personally I don't like racking things that far over my head.
I don't really care about that, myself - racking any serious number
is a two-person job anyway. but taller racks make some sense to me,
since open space above the rack is pretty much wasted and/or
a design flaw. (that is, you want your hot-air plenum to seal
the top of the rack, which is most easily done with a drop-ceiling
that meets the top.)
density is an interesting question - if nodes are 350W, does it make
sense to have 50 of them in a rack? 17.5 KW requires 5 tons of cooling,
and as a rule of thumb 5 perf tiles. you can probably get by with
2-ish high-perf tiles if your air pressure is good. but that means
your cold rows will be at least 4 tiles wide, possibly more.
oops, wasn't density the argument for taller racks?
> We've being switching cabinets in one of our datacenters to 220volt
> service to support the sort of density we're seeing without running new
sure, there's no downside to 220 afaikt. one thing I don't fully
understand is where the 80% figure comes from. just a fudge-factor,
and what if you wind up always using that extra capacity?
presumably an L6-30 circuit is actually safe to run at 30...
More information about the Beowulf