Working with backup sets : Microsoft Exchange Server backup sets (Windows) : Restoring a Microsoft Exchange Server backup set : Specifying performance options
 
Specifying performance options
Special performance options in the Select restore performance options screen are intended for large backup sets in high performance environments.
• For typical use, keep DS-Client’s default settings and click Next to proceed to the next screen.
More information in F1 help: "Select Restore Performance Options (Windows DS-Client)"