Parallel Processing Factor (Environment setting)

Tools that honor the Parallel Processing Factor environment will divide and perform operations across multiple processes.

Many modern computers include multiple-core CPUs. Spreading a geoprocessing operation across multiple processes can speed up performance by taking advantage of more than one core. The performance benefit of parallel processing varies from tool to tool.

Usage notes

Dialog syntax

Parallel Processing Factor—The number of processes across which a tool will spread its operation.

Scripting syntax

arcpy.env.parallelProcessingFactor = string



empty string (blank)

Let each tool determine how many processes to use. This is the default.


Do not spread operations across multiple processes.


Use the specified number of processes.


Calculate the number of processes using the specified percentage: Number of processes = number of system cores * n / 100.

parallelProcessingFactor syntax

Script example

import arcpy

# Use half of the cores on the machine.
arcpy.env.parallelProcessingFactor = "50%"

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