57 lines
1.5 KiB
ReStructuredText
57 lines
1.5 KiB
ReStructuredText
OPT package
|
|
===========
|
|
|
|
The OPT package was developed by James Fischer (High Performance
|
|
Technologies), David Richie, and Vincent Natoli (Stone Ridge
|
|
Technologies). It contains a handful of pair styles whose compute()
|
|
methods were rewritten in C++ templated form to reduce the overhead
|
|
due to if tests and other conditional code.
|
|
|
|
Required hardware/software
|
|
""""""""""""""""""""""""""
|
|
|
|
Any hardware. Any compiler.
|
|
|
|
Building LAMMPS with the OPT package
|
|
""""""""""""""""""""""""""""""""""""
|
|
|
|
See the :ref:`Build extras <opt>` page for instructions.
|
|
|
|
Run with the OPT package from the command-line
|
|
""""""""""""""""""""""""""""""""""""""""""""""
|
|
|
|
.. code-block:: bash
|
|
|
|
lmp_mpi -sf opt -in in.script # run in serial
|
|
mpirun -np 4 lmp_mpi -sf opt -in in.script # run in parallel
|
|
|
|
Use the "-sf opt" :doc:`command-line switch <Run_options>`, which will
|
|
automatically append "opt" to styles that support it.
|
|
|
|
Or run with the OPT package by editing an input script
|
|
""""""""""""""""""""""""""""""""""""""""""""""""""""""
|
|
|
|
Use the :doc:`suffix opt <suffix>` command, or you can explicitly add an
|
|
"opt" suffix to individual styles in your input script, e.g.
|
|
|
|
.. code-block:: LAMMPS
|
|
|
|
pair_style lj/cut/opt 2.5
|
|
|
|
Speed-up to expect
|
|
""""""""""""""""""
|
|
|
|
You should see a reduction in the "Pair time" value printed at the end
|
|
of a run. On most machines for reasonable problem sizes, it will be a
|
|
5 to 20% savings.
|
|
|
|
Guidelines for best performance
|
|
"""""""""""""""""""""""""""""""
|
|
|
|
Just try out an OPT pair style to see how it performs.
|
|
|
|
Restrictions
|
|
""""""""""""
|
|
|
|
None.
|