If you have sufficient space on the local Exchange system for the temporary data store, then the defrag of that data store will take approximately 1 hour per 9GB (best case scenario).
If you don't have sufficient space on the local Exchange system for the temporary data store and have told PerfectDisk for Exchange to store the temporary file on network storage, then the defrag of that data store will take approximately 1 hour per 4GB.
Please note that this depends on your configuration selections, network speed, and how much space is being reclaimed from the information stores.
Related Topics
§ Defragmenting an Exchange Data Store
§ How much free space is required to defragment an Exchange data store?
§ How often should I defragment an Exchange data store?
§ What versions of Exchange Server does PerfectDisk support?