[Beowulf] Academic sites: who pays for the electricity?

Brent M. Clements bclem at rice.edu
Wed Feb 16 08:48:34 PST 2005


I would suggest asking this on the Educause CIO mailing list.

Anyone can join as long as your from a educational entity.

-Brent

> A/C are paid for by the school.  To do so they take "overhead"
> out of every grant.  Partially as a consequence of this they
> typically have a very poor ability to meter usage on a room
> by room basis.
>
> Now somewhere between the 10 node Pentium II beowulf sitting on
> a lab bench and the 1000 node dual P4 Xeon beowulf in a machine
> room that takes up half the basement the cost of the electricity
> (both for power and A/C) goes from  a minor expense to a major
> one.  Really major. For instance, in that hypothetical large machine,
> at 10 cents per kilowatt hour (a round number), assuming 100 watts
> per CPU (another round number) that's:
>
>  1000  (nodes) *
>     2  (cpus/node) *
>     .1 (kilowatts/cpu) *
>     .1 (dollars/kilowatt-hour) *
>  365   (days /year) *
>   24   (hours/day) =
> -----------------------
>  175200 dollars/year
>
> The A/C expense is going to vary tremendously depending upon
> the outside temperature.  It's going to be much higher for us
> in Southern California than for a site in Anchorage.
>
> "Typical" lab usage is widely variable but I'd be amazed
> if most biology or chemistry labs burn through even 1/10th this
> much for the equivalent lab area.  Some physics lab running
> a tokamak might come close.
>
>
> Anyway, the question is, have any of the universities said "enough
> is enough" and started charging these electricity costs directly?
> If so, what did they use for a cutover level, where usage was
> "above and beyond" overhead?
>
>> From an economic perspective having electricity and A/C come out
> of overhead (without limit) grossly distorts the true cost
> of the project over time and can lead to choices which increase
> the total overall cost. For instance, the use of Xeons instead of
> Opterons has little effect on TCO if somebody else is picking
> up the electricity tab, but could change the power consumption
> significantly on a large project.
>
> Regards,
>
> David Mathog
> mathog at caltech.edu
> Manager, Sequence Analysis Facility, Biology Division, Caltech
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