Incompressible Navier-Stokes problem with Taylor-Green forcing using the Dedalus pseudospectral framework. To run these problems, first install Dedalus (and on bitbucket).

Once Dedalus is installed and activated, do the following:

#!bash
mpiexec_mpt -n 256 python3 incompressible_NS_TG.py --mesh=16,16

To obtain sparsity plots of the implicit matrices, use the --verbose keyword:

#!bash
python3 incompressible_NS_TG.py --verbose --niter=2 --nx=4 --ny=4 --nz=128

Here we've run a reduced horizontal resolution case so that it can be readily completed by a single core.

For scaling tests on NASA/Pleiades:

#!bash
python3 scaling.py run incompressible_NS_TG.py --3D 128 --min-cores=128 --max-cores=512 --MPISGI

The following block of code, run on NASA/Pleiades Broadwell nodes (28 cores/node) using an MPI-SGI stack,

#!bash
python3 scaling.py run incompressible_NS_TG.py --3D 128 --min-cores=16 --max-cores=2048 --MPISGI --niter=10
python3 scaling.py run incompressible_NS_TG.py --3D 256 --min-cores=64 --max-cores=2048 --MPISGI --niter=10
python3 scaling.py run incompressible_NS_TG.py --3D 512 --min-cores=256 --max-cores=2048 --MPISGI --niter=10

python3 scaling.py plot scaling_data_512x512x512.db scaling_data_256x256x256.db scaling_data_128x128x128.db 

recreates this scaling plot:

Ideal scaling is indicated by dashed black lines, extrapolated from the lowest core count case in all cases. At each core count, a cloud of points are shown sampling a variety of processor mesh configurations. Generally, the configuration of the processor mesh has little impact on overall performance.

Contact the exoweather team for more details.