Quantum Espresso 6.2.1 User Notes.

Version 6.2.1 of Quantum Espresso has been benchmarked on bebop for both the Broadwell and Knights Landing nodes.  These builds can be found in subfolders of /soft/espresso/6.2.1/bebop/{bdw,bdw-omp,knl-omp}.  There are sample bash scripts which can be submitted as batch jobs through slurm (sbatch) for each architecture in these folders.

On the PSIWAT benchmark, the KNL nodes are competitive with the Broadwell nodes.  On a per core basis, the KNLs are 60% of a BDW core on 2, 4 and 16 nodes, which makes them cost-effective on KNL over the BDW nodes.

Note that the MPI/OpenMP hybrid version will give better parallel scaling on more nodes than the pure MPI builds.  A comparison of the MPI/OpenMP hybrid binaries on BDW and KNL nodes is shown below.  These binaries can be found in the bdw-omp/bin and knl-omp/bin subfolders of  /soft/espresso/6.2.1/bebop.  The binaries in /soft/espresso/6.2.1/bebop/bdw/bin are pure MPI binaries.

Note that the most recent version of Quantum Espresso built on bebop is 6.4.1.  It performance should be slightly better than 6.2.1 and can run with the same scripts.  The broadwell build in /soft/espresso/6.4.1/bdw/bin is a pure MPI build.  The knl build in /soft/espresso/6.4.1/knl/bin is a hybrid MPI/openMP build.  The knl build in  soft/espresso/6.4.1/knl/bin is also a hybrid MPI/openMP with the libxc library added to expand the functionals which can be used in Quantum Espresso.

Please review this presentation for more details on to use Quantum Espresso on the KNL nodes.