OMP2012 Flag Description
Colfax International Intel Xeon Phi 7210, 1.30GHz, SMT off, Turbo off, flat (MCDRAM Preferred)

Test sponsored by Indiana University

Copyright © 2012 Intel Corporation. All Rights Reserved.

Base Compiler Invocation

C benchmarks

C++ benchmarks

Fortran benchmarks

Base Portability Flags




Base Optimization Flags

C benchmarks

C++ benchmarks

Fortran benchmarks

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.

Shell, Environment, and Other Software Settings

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

Sw environment from Intel-ic16.0-linux64

SPEC OMP2012 Flag Description for the Intel(R) C/C++ Compiler for IA32 and Intel 64 applications and Intel(R) Fortran Compiler for IA32 and Intel 64 applications

Specify stack size to be allocated for each thread.
The value for the environment variable KMP_AFFINITY affects how the threads from an auto-parallelized program are scheduled across processors.
Specifying disabled completely disables the thread affinity interfaces. This forces the OpenMP run-time library to behave as if the affinity interface was not supported by the operating system. This includes the low-level API interfaces such as kmp_set_affinity and kmp_get_affinity, which have no effect and will return a nonzero error code.
For loops running with OpenMP schedule "static", this results in (#iterations/#threads) iterations--rounded to the next lower integer--being allocated to most threads, with at most one additional iteration being allocated to some threads. Although the largest number of iterations assigned to any thread remains the same, this results in a more even sharing of iterations between threads, which may sometimes lead to a performance improvement relative to the default static thread distribution.
OMP_DYNAMIC=[ 1 | 0 ] Enables (1) or disables (0) the dynamic adjustment of the number of threads.
Enables (TRUE) or disables (FALSE) nested parallelism.
Sets the time, in milliseconds, that a thread should wait, after completing the execution of a parallel region, before sleeping.
Selects the OpenMP run-time library.
Set stack size to unlimited
The command "ulimit -s unlimited" is used to set the stack size limit to unlimited.

Sw environment from colfax-knl

SPEC OMP2012 Platform Description

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.

Firmware / BIOS / Microcode 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 divide 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.

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.
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Copyright 2012-2017 Standard Performance Evaluation Corporation
Tested with SPEC OMP2012 v1.1.
Report generated on Wed Jan 11 12:09:31 2017 by SPEC OMP2012 flags formatter v538.