This topic describes the OpenMP* environment variables (with the OMP_ prefix) and Intel-specific environment variables (with the KMP_ prefix).
| Variable | Description | Default |
|---|---|---|
| OMP_SCHEDULE | Sets the runtime schedule type and chunk size. | STATIC ( no chunk size specified) |
| OMP_NUM_THREADS | Sets the number of threads to use during execution. | Number of processors |
| OMP_DYNAMIC | Enables (TRUE) or disables (FALSE) the dynamic adjustment of the number of threads. | FALSE |
| OMP_NESTED | Enables (TRUE) or disables (FALSE) nested parallelism. | FALSE |
| Environment Variable | Description | Default |
|---|---|---|
| KMP_LIBRARY | Selects the OpenMP run-time library throughput. The options for the variable value are: serial, turnaround, or throughput indicating the execution mode. The default value of throughput is used if this variable is not specified. | throughput (execution mode) |
| KMP_STACKSIZE | Sets the number of bytes to allocate for each parallel thread to use as its private stack. Use the optional suffix b, k, m, g, or t, to specify bytes, kilobytes, megabytes, gigabytes, or terabytes. | IA-32: 2m Itanium® compiler: 4m |