Developer Reference

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.

Product and Performance Information

1

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