Suggested parallelism is valid for the native execution environment when the Maximum Parallelism property is assigned to a value greater than one or to a parameter. Suggested number of parallel threads that process the transformation pipeline stage.
When you define a suggested parallelism value for a transformation, the Data Integration Service considers the value when it determines the optimal number of threads for that transformation pipeline stage. You might want to define a suggested parallelism value to optimize performance for a transformation that contains many ports or performs complicated calculations.
Default is Auto, which means that the transformation uses the maximum parallelism value defined for the mapping. Maximum is 64.