Huw Lynes wrote:
On Wed, 2009-01-21 at 12:33 -0800, Greg Lindahl wrote:
On Wed, Jan 21, 2009 at 10:57:42AM -0500, Mark Hahn wrote:
I guess our premises are quite different.
Yes, they are. Hence your statement about "obviously burning money"
was a bit of an over-generalization ;)
There are HPC systems that want UPSes, namely ones that do
mission-critical things, like weather forecasts, and spooky work.
Most university HPC systems don't fall into that category. Most
business websites do fall into the UPS category. But other than that,
my cluster looks pretty much like an HPC cluster, albeit one with
only gbit ethernet and lots of local disk.
Our new HPC data-centre is completely UPSed. With the UPS sized to
bridge to the diesel generator that protects the entire building. We may
be a slightly special case in that the mains in Cardiff is horrifically
dirty. We've seen very expensive pieces of killed by power spikes on a
couple of occasions.
Our current monitoring shows the UPS cutting over to battery at least
twice a month. So at least in our instance UPS protection is worth every
penny.
Hi Huw, list
Regarding bad power, Cardiff is not so special. :)
You're not alone.
We have aerial power lines serving our suburban/rural campus,
with thunderstorms, fallen tree branches,
or electrocuted squirrels, spiking, shaking,
or cutting power many times a year.
The buildings have diesel generators,
not only because of computer rooms, but also for
expensive/delicate lab equipment,
protected by UPSs of several sizes and types,
from big Lieberts to small VA units.
With the generators, we only need a modest battery time also.
Our UPSs are worth having for the reasons you presented.
Toasting computers or mass spectrometers with electrical
spikes is no fun.
Gus Correa
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Gustavo Correa
Lamont-Doherty Earth Observatory - Columbia University
Palisades, NY, 10964-8000 - USA
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