SPEC MPI2007 Flag Description for the Intel(R) C++ Compiler 14.0 for IA32 and Intel 64 applications and Intel(R) Fortran Compiler 14.0 for IA32 and Intel 64 applications

Copyright © 2013 Intel Corporation. All Rights Reserved.

Sections

Selecting one of the following will take you directly to that section:


Optimization Flags


Portability Flags


Compiler Flags


System and Other Tuning Information

Intel(R) MPI Library 2017 for Linux* options and environment variables

Job startup command flags

-n <# of processes> or -np <# of processes>

Use this option to set the number of MPI processes to run the current arg-set.

-perhost <# of processes> or -ppn <# of processes>

Use this option to place the indicated number of consecutive MPI processes on every host in group round robin fashion. The number of processes to start is controlled by the option -n as usual.

-genv <ENVVAR> <value>

Use this option to set the <ENVVAR> environment variable to the specified <value> for all MPI processes.

Environment variables

I_MPI_FABRICS=<fabric>|<intra-node fabric>:<inter-node fabric>

Select the particular network fabric to be used.

tmi - Tag Matching Interface (TMI)-capable network fabrics, such as Intel True Scale Fabric and Myrinet* (through TMI).

shm - Shared-memory only

dapl - Direct Access Programming Library* (DAPL)-capable network fabrics, such as InfiniBand* and iWarp* (through DAPL)

ofi - OpenFabrics Interfaces* (OFI)-capable network fabrics, such as Intel True Scale Fabric and Ethernet (through OFI API).

I_MPI_FALLBACK=<0|1>

Set this environment variable to enable fallback to the available fabric. It is valid only for rdssm and rdma modes.

Fall back to the shared memory and/or socket fabrics if initialization of the DAPL* fabric fails. This is the default value.

Terminate the job if the fabric selected by the I_MPI_DEVICE environment variable cannot be initialized.

I_MPI_COMPATIBILITY=<value>

Available values:

3 - The Intel MPI Library 3.x compatible mode

4 - The Intel MPI Library 4.0.x compatible mode

Set this environment variable to choose the Intel MPI Library runtime compatible mode. By default, the library complies with the MPI-3.1 standard.

I_MPI_HYDRA_PMI_CONNECT=<value>

Available values:

nocache - Do not cache PMI messages

cache - Cache PMI messages on the local pmi_proxy management processes to minimize the number of PMI requests. Cached information is automatically propagated to child management processes

lazy-cache - cache mode with on-demand propagation. This is the default value.

alltoall - Information is automatically exchanged between all pmi_proxy before any get request can bedone.

Define the processing method for PMI messages.