MPI2007 Flag Description
Colfax International Intel Xeon Phi 7210, 1.30 GHz, SMT on, Turbo off, flat (MCDRAM preferred)

Test sponsored by Indiana University

Copyright © 2016 Intel Corporation. All Rights Reserved.

Base Compiler Invocation

C benchmarks

C++ benchmarks


Fortran benchmarks

Benchmarks using both Fortran and C

Base Portability Flags





Base Optimization Flags

C benchmarks

C++ benchmarks


Fortran benchmarks

Benchmarks using both Fortran and C

Implicitly Included Flags

This section contains descriptions of flags that were included implicitly by other flags, but which do not have a permanent home at SPEC.

System and Other Tuning Information

This result has been formatted using multiple flags files. The "platform settings" from each of them appears next.

Platform settings from EM64T_Intel_flags

SPEC MPI2007 Flag Description for the Intel(R) C++ Compiler 16.0 for IA32 and Intel 64 applications and Intel(R) Fortran Compiler 16.0 for IA32 and Intel 64 applications

Intel(R) MPI Library 4.1.1 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>

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.


Use this option to allow parallel fast starting of mpd daemons under one local root. No daemon checking is performed.

-genv <ENVVAR> <value>

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

Environment variables


Select the particular network fabric to be used.

sock - Sockets

shm - Shared-memory only (no sockets)

ssm - Combined sockets + shared memory (for clusters with SMP nodes)

rdma - RDMA-capable network fabrics including InfiniBand*, Myrinet* (via DAPL*)

rdssm - Combined sockets + shared memory + DAPL* (for clusters with SMP nodes and RDMA-capable network fabrics)


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.

Platform settings from colfax-knl

SPEC Flag Description for Intel Xeon Phi BIOS Setup and Tuning

Machine Configurations

BIOS settings

Simultaneous Multithreading

On 2nd generation Intel Xeon Phi processor and co-processors, Simultaneous Multithreading (SMT), permits 4 independent threads of execution on each core.

Cluster Mode:

This BIOS switch allows 5 options "All2All", "SNC-2", "SNC-4", "Hemisphere" and "Quadrant". Quadrant mode divides the chip into 4 virtual Quadrants. Quadrant mode can shorten the route length to memory, and that enable us to enlarge the bandwidth of memory.

Memory Mode

This BIOS switch allows 3 options "Cache", "Flat", and "Hybrid". Flat mode: the 16GB high bandwidth on-chip MCDRAM shares a single contiguous address space as the DRAM and is partitioned onto the second NUMA node. Cache mode: the MCDRAMs is used as the cache of DDR memory. Hybrid mode: a portion of the MCDRAM is used in flat mode, the rest is used as cache.

Turbo Mode

Enabling this switch allows the processor to provide more computing performance at short notice by increasing the frequency above nominal frequency.

Other Tuning Information

numactl [ --preferred node ] [ --membind nodes ]

Control NUMA policy for processes or shared memory.

--membind=nodes, -m nodes

Only allocate memory from nodes. Allocation will fail when there is not enough memory available on these nodes. Nodes may be specified as noted above

--preferred=node, -p node

Preferably allocate memory on node, but if memory cannot be allocated then fall back to other nodes. This option takes only a single node number. Relative notation may be used.

Flag description origin markings:

[user] Indicates that the flag description came from the user flags file.
[suite] Indicates that the flag description came from the suite-wide flags file.
[benchmark] Indicates that the flag description came from a per-benchmark flags file.

The flags files that were used to format this result can be browsed at,

You can also download the XML flags sources by saving the following links:,

For questions about the meanings of these flags, please contact the tester.
For other inquiries, please contact
Copyright 2006-2010 Standard Performance Evaluation Corporation
Tested with SPEC MPI2007 v2.0.1.
Report generated on Wed Jan 11 12:44:21 2017 by SPEC MPI2007 flags formatter v1445.