On Thu, Jun 6, 2013 at 5:48 AM, Nathan Moore <ntmo...@gmail.com> wrote: > Does anyone know, > off-hand, how often these big machines run with all compute nodes dedicated > to a single message-passing job?
Once, for the initial HPL run? :) > Am I far off the mark? No, that's indeed what happens on most supers I've seen. Even if some codes are capable of running to the (almost) full scale of the machine, such large runs are quite marginal. They often take place before the system enters production, to demonstrate its capabilities, or from time to time on a specific breakthrough project, usually along with some media coverage. Bust most of the time, smaller jobs occupy the slots. Those systems are mainly shared resources, and monopolizing the whole thing for a single application/group/user is often not the best way to make the investment profitable. > Along similar lines, has Google or Amazon ever published their batch job > capacity (it must be in petaflops...) I'm not sure how it can compare. From what I understand, their systems are not quite HPC-like, in the sense they're less tightly-coupled, and often geographically distributed. That means high latencies and grumpy MPI. So even if we could count the number of processors running their servers, and multiply that by the individual Flops of said CPUs, we would probably get a large number, but not necessarily a point of comparison with the Top500 machines. Cheers, -- Kilian _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
