[Beowulf] crunch per kilowatt: GPU vs. CPU

[David Mathog]

Although the folks now using CUDA are likely most interested in crunch
per unit time (time efficiency), perhaps some of you have measurements
and can comment on the energy efficiency of GPU vs. CPU computing?  That
is, which uses the fewest kilowatts per unit of computation.  My guess
is that the most energy efficient solution is still CPU based,  because
Intel and AMD have both worked hard on that issue.  Seems like this sort
of information would be useful when comparing CPU and GPU based
solutions, in order to determine the overall cost efficiency (total
crunch /(purchase price + operating expense).

Thanks,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech