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, the Intel® MPI Library loads tuning settings in a binary format. If it is not possible, the 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

1

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