Intel® MPI Library Developer Reference for Windows* OS

ID 768734
Date 3/31/2023
Public

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OFI*-capable Network Fabrics Control

I_MPI_OFI_DRECV

Control the capability of the direct receive in the OFI fabric.

Syntax

I_MPI_OFI_DRECV=<arg>

Arguments

<arg> Binary indicator
enable | yes | on | 1 Enable direct receive. This is the default value
disable | no | off | 0 Disable direct receive

Description

Use the direct receive capability to block MPI_Recv calls only. Before using the direct receive capability, ensure that you use it for single-threaded MPI applications and check if you have selected OFI as the network fabric by setting I_MPI_FABRICS=ofi.

I_MPI_OFI_LIBRARY_INTERNAL

Control the usage of libfabric* shipped with the Intel® MPI Library.

Syntax

I_MPI_OFI_LIBRARY_INTERNAL=<arg>

Arguments

<arg> Binary indicator
enable | yes | on | 1 Use libfabric from the Intel MPI Library
disable | no | off | 0 Do not use libfabric from the Intel MPI Library

Description

Set this environment variable to disable or enable usage of libfabric from the Intel MPI Library. The variable must be set before sourcing the vars.bat script.

Example

> set I_MPI_OFI_LIBRARY_INTERNAL=1
> call <installdir> \env\vars.bat

Setting this variable is equivalent to passing the -ofi_internal option to the vars.bat script.

For more information, refer to the Intel® MPI Library Developer Guide, section Libfabric* Support.

I_MPI_OFI_TAG_DYNAMIC

Enable dynamic tag partitioning.

Syntax

I_MPI_OFI_TAG_DYNAMIC=<arg>

Arguments

<arg> Binary indicator
enable | yes | on | 1 Enable automatic OFI tag partitioning
disable | no | off | 0 Use static OFI tag layout. This is the default value

Description

Set this environment variable to enable dynamic OFI Netmod tag partitioning based on the run configuration. You can use it to get larger MPI tag space or to improve scalability in large-scale runs.