Developer Guide

Contents

Setting the Number of Threads Using an OpenMP* Environment Variable

You can set the number of threads using the environment variable
OMP_NUM_THREADS
. To change the number of OpenMP threads, in the command shell in which the program is going to run,
enter:
set OMP_NUM_THREADS=
<number of threads to use>
.
Some shells require the variable and its value to be exported:
export OMP_NUM_THREADS=
<number of threads to use>
.
You can alternatively assign value to the environment variable using Microsoft Windows*
OS Control Panel.
Note that you will not benefit from setting this variable on Microsoft Windows* 98 or
Windows* ME because multiprocessing is not supported.

Product and Performance Information

1

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