[Beowulf] Electricity cost: a critical survival issue of our ICT infrastructures.

Peter St. John peter.st.john at gmail.com
Mon Apr 8 06:00:31 PDT 2013


I'm no physicist, but I did a back-of-the-envelope calculation (available
if you are curious, my "envelope" is vi, but since I'm a lousy physicist I
gloss), using
http://en.wikipedia.org/wiki/Limits_to_computation
(which connects the cosmic microwave background radiation to a limit for
energy per state change) and guesstimating a million state changes per FLOP
(I don't know how to count the state changes to perform e.g. a multiply of
two registers, because a circuit to do it would have current or taut
strings or something that themselves change state), and got 10^-15 joule
per FLOP or 10^-15 watt per FLOPS, about half a million times more
efficient than the Blue Gene doing 2000 MFLOPS per watt.

I'm just saying, the theoretical limits are a ways off yet. In the short
term power costs for growing clusters for growing computing demand looks
bleak maybe, but I think there's lots of elbow room yet for clever
improvements. Like chilling my mineral oil in the fridge overnight before
filling my desktop case with it :/
Peter


On Mon, Apr 8, 2013 at 5:13 AM, Hearns, John <john.hearns at mclaren.com>wrote:

> On Mon, Apr 08, 2013 at 08:58:19AM +0000, Hearns, John wrote:
>
> > a) humankind will inevitably demand, build and find uses for computing
> systems with ever increasing numbers of fixed point of
> > floating point operations per second.
> > Devil's advocate time - we can simply declare that no new faster system
> will be built
>
> Photovoltaics actually shaves off peak quite nicely, and reduces
> the price of electricity. If you don't want to invest into MWh
> storage (redox flow or otherwise) you could checkpoint a bit
> before sunset, and resume when power is available.
>
>
> You mean.... supercomputing types coming out in the DAYLIGHT? Working
> normal hours?
> That will never work.
>
>
> Joking aside, that is a good idea. Just have to manage user expectations
> when there is a cloudy day!
>
>
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