Developer Reference

  • 2020 Update 2
  • 07/15/2020
  • Public Content

Tuning Environment Variables

I_MPI_TUNING_MODE
Select the tuning method.

Syntax

I_MPI_TUNING_MODE=<arg>
A
rgument
<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

/p>
<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

/p>
<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

/p>
<path>
A path to a JSON file with tuning settings.

Description

Set this environment variable to load tuning settings in a JSON format.
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

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804