Developer Reference

Tuning Environment Variables

I_MPI_TUNING_MODE
Select the tuning method.
Syntax
I_MPI_TUNING_MODE=
<arg>
Argument
<arg>
Description
none
Disable tuning modes. This is the default value.
auto
Enable autotuner.
auto:application
Enable autotuner with application focused strategy (alias for auto).
auto:cluster
Enable autotuner without application specific logic. This is typically performed with the help of benchmarks (for example, IMB-MPI1) and proxy applications.
Description
Set this environment variable to enable the autotuner functionality and set the autotuner strategy.
I_MPI_TUNING_BIN
Specify the path to tuning settings in a binary format.
Syntax
I_MPI_TUNING_BIN=
<path>
Argument
<path>
A path to a binary file with tuning settings. By default, Intel® MPI Library uses the binary tuning file located at <
$I_MPI_ROOT/etc>.
Description
Set this environment variable to load tuning settings in a binary format.
I_MPI_TUNING_BIN_DUMP
Specify the file for storing tuning settings in a binary format.
Syntax
I_MPI_TUNING_BIN_DUMP=
<filename>
Argument
<filename>
A file name of a binary that stores tuning settings. By default, the path is not specified.
Description
Set this environment variable to store tuning settings in a binary format.
I_MPI_TUNING
Load tuning settings in a JSON format.
Syntax
I_MPI_TUNING=
<path>
Argument
<path>
A path to a JSON file with tuning settings.
Description
Set this environment variable to load tuning settings in a JSON format.
Note:
The tuning settings in the JSON format are produced by the mpitune utility.
By default, Intel® MPI library loads tuning settings in a binary format. If it is not possible, Intel MPI Library loads the tuning file in a JSON format specified through the
I_MPI_TUNING environment variable.
Thus, to enable JSON tuning, turn off the default binary tuning:
I_MPI_BIN="". If it is not possible to load tuning settings from a JSON file and in a binary format, the default tuning values are used.
You do not need to turn off binary or JSON tuning settings if you use
I_MPI_ADJUST family environment variables. The algorithms specified with
I_MPI_ADJUST environment variables always have priority over binary and JSON tuning settings.

Product and Performance Information

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Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.