Working with backup sets : VSS-aware backup sets (Windows) : Restoring a VSS-aware backup set : Specifying performance options
 
Specifying performance options
On the Select restore performance options page, the special performance options are intended for large backup sets in high performance environments.
• For typical use, keep DS-Client’s default settings, and then click Next.
More information in F1 help: "Select Restore Performance Options (Windows DS-Client)"