On Wed, Apr 5, 2017 at 10:26 PM, Jed Brown <[email protected]> wrote:
> Matthew Knepley <[email protected]> writes: > > > On Wed, Apr 5, 2017 at 12:23 PM, Justin Chang <[email protected]> > wrote: > > > >> I simply ran these KNL simulations in flat mode with the following > options: > >> > >> srun -n 64 -c 4 --cpu_bind=cores numactl -p 1 ./ex48 .... > >> > >> Basically I told it that MCDRAM usage in NUMA domain 1 is preferred. I > >> followed the last example: http://www.nersc.gov/users/ > >> computational-systems/cori/configuration/knl-processor-modes/ > >> > > > > Right. I think, from the prior discussion, that -m 1 causes the run to > fail > > if you spill out of MCDRAM. I think that is usually > > what we want since it makes things easier to interpret and running MKL > from > > DRAM is like towing your McLaren with > > your Toyota. > > I'm not sure whether getting the Intel acronyms mixed up (KNL vs MKL) > makes the quote above better or worse. > Too cryptic. Are you saying that this cannot be what is happening? How would you explain the drop off in performance? Matt -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
