NERSCPowering Scientific Discovery Since 1974

KNL Office Hours Starting this Friday and Every Friday in May

April 22, 2019 by Rebecca Hartman-Baker

NERSC will hold virtual office hours over Zoom beginning this Friday, April 26 from 9:00 am to 3:00 pm Pacific Time and every Friday in May, to help users get their codes running efficiently on the Cori KNL nodes.

For many users, running efficiently on the KNL nodes is as simple as making sure that their job script is set to request the proper thread affinity on the node, and their executable is compiled correctly to exploit the KNL architecture. We have seen a performance gap shrink by a factor of 7 just with these two simple steps.

Other user codes may require some relatively straightforward code changes (for example, a loop reordering to exploit vectorization). Profiling the code is the first step towards finding these hot spots or bottlenecks.

During the KNL Office Hours, NERSC experts will be on hand to help you take these steps. Please (virtually) drop by for help with

  • Setting up your job script for proper thread affinity,
  • Compiling your code with the best optimization flags,
  • Getting started with profiling your code, and/or
  • Interpreting the results of profiling, and advice on how to proceed.


KNL Office Hours will be held from 9:00 am to 3:00 pm (Pacific Time) on the following dates (all Fridays):

  • April 26
  • May 3
  • May 10
  • May 17
  • May 24
  • May 31

See the event on the NERSC Public Events Calendar.

How to Participate

To connect to the KNL Office Hours Zoom meeting:

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