Performance tuning of a Fast Load Script- - response (3) by ulrich

it will depend on your source data. 
In some cases network bandwidth is an issue. If you have a wide interface and it is defined with fixed and it contains many variable length char target columns  it can be a considered to change the source file as well to varchar as in this case the volume to be transfered can be drastically reduced.
Also consider if NO PI is an option in your approach.