Prentice, I echo what Joe says. When doing benchmarking with HPL or SPEC benchmarks, I would optimise the BIOS settings to the highest degree I could. Switch off processor C) states As Joe says you need to look at what the OS is runnign in the background. I would disable the Bright cluster manager daemon for instance.
85% of theoretical peak on an HPL run sounds reasonable to me and I would get fogures in that ballpark. For your AMDs I would start by choosing one system, no interconnect to cloud the waters. See what you can get out of that. On 22 February 2018 at 15:45, Joe Landman <joe.land...@gmail.com> wrote: > > > On 02/22/2018 09:37 AM, Prentice Bisbal wrote: > >> Beowulfers, >> >> In your experience, how close does actual performance of your processors >> match up to their theoretical performance? I'm investigating a performances >> issue on some of my nodes. These are older systems using AMD Opteron 6274 >> processors. I found literature from AMD stating the theoretical performance >> of these processors is 282 GFLOPS, and my LINPACK performance isn't coming >> close to that (I get approximately ~33% of that). The number I often hear >> mentioned is actual performance should be ~85%. of theoretical performance >> is that a realistic number your experience? >> > > 85% makes the assumption that you have the systems configured in an > optimal manner, that the compiler doesn't do anything wonky, and that, to > some degree, you isolate the OS portion of the workload off of most of the > cores to reduce jitter. Among other things. > > At Scalable, I'd regularly hit 60-90 % of theoretical max computing > performance, with progressively more heroic tuning. Storage, I'd > typically hit 90-95% of theoretical max (good architectures almost always > beat bad ones). Networking, fairly similar, though tuning per use case > mattered significantly. > > >> I don't want this to be a discussion of what could be wrong at this >> point, we will get to that in future posts, I assure you! >> >> > -- > Joe Landman > t: @hpcjoe > w: https://scalability.org > > > _______________________________________________ > 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 >
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