forked from lijiext/lammps
use Hyper-Threading consistently
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@ -93,12 +93,12 @@ The "t Nt" option specifies how many OpenMP threads per MPI task to
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use with a node. The default is Nt = 1, which is MPI-only mode. Note
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use with a node. The default is Nt = 1, which is MPI-only mode. Note
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that the product of MPI tasks * OpenMP threads/task should not exceed
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that the product of MPI tasks * OpenMP threads/task should not exceed
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the physical number of cores (on a node), otherwise performance will
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the physical number of cores (on a node), otherwise performance will
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suffer. If hyperthreading is enabled, then the product of MPI tasks *
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suffer. If Hyper-Threading (HT) is enabled, then the product of MPI
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OpenMP threads/task should not exceed the physical number of cores *
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tasks * OpenMP threads/task should not exceed the physical number of
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hardware threads. The "-k on" switch also issues a "package kokkos"
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cores * hardware threads. The "-k on" switch also issues a
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command (with no additional arguments) which sets various KOKKOS
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"package kokkos" command (with no additional arguments) which sets
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options to default values, as discussed on the "package"_package.html
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various KOKKOS options to default values, as discussed on the
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command doc page.
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"package"_package.html command doc page.
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The "-sf kk" "command-line switch"_Run_options.html will automatically
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The "-sf kk" "command-line switch"_Run_options.html will automatically
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append the "/kk" suffix to styles that support it. In this manner no
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append the "/kk" suffix to styles that support it. In this manner no
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@ -149,7 +149,7 @@ Intel Knight's Landing (KNL) Xeon Phi:
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KNL Intel Phi chips have 68 physical cores. Typically 1 to 4 cores are
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KNL Intel Phi chips have 68 physical cores. Typically 1 to 4 cores are
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reserved for the OS, and only 64 or 66 cores are used. Each core has 4
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reserved for the OS, and only 64 or 66 cores are used. Each core has 4
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hyperthreads,so there are effectively N = 256 (4*64) or N = 264 (4*66)
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Hyper-Threads,so there are effectively N = 256 (4*64) or N = 264 (4*66)
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cores to run on. The product of MPI tasks * OpenMP threads/task should
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cores to run on. The product of MPI tasks * OpenMP threads/task should
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not exceed this limit, otherwise performance will suffer. Note that
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not exceed this limit, otherwise performance will suffer. Note that
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with the KOKKOS package you do not need to specify how many KNLs there
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with the KOKKOS package you do not need to specify how many KNLs there
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@ -363,7 +363,7 @@ specified with the OMP_NUM_THREADS environment variable or the {omp}
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keyword). The extra thread is dedicated for performing part of the
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keyword). The extra thread is dedicated for performing part of the
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"PPPM solver"_kspace_style.html computations and communications. This
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"PPPM solver"_kspace_style.html computations and communications. This
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can improve parallel performance on processors supporting
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can improve parallel performance on processors supporting
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Simultaneous Multithreading (SMT) such as Hyperthreading on Intel
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Simultaneous Multithreading (SMT) such as Hyper-Threading (HT) on Intel
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processors. In this mode, one additional thread is generated per MPI
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processors. In this mode, one additional thread is generated per MPI
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process. LAMMPS will generate a warning in the case that more threads
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process. LAMMPS will generate a warning in the case that more threads
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are used than available in SMT hardware on a node. If the PPPM solver
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are used than available in SMT hardware on a node. If the PPPM solver
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