One of the most common questions about Dell Migration Suite for SharePoint / Migration Manager for SharePoint is how long it will take to complete a migration. How many GBs per minute/hour/day can we move? The answer to these questions depends on many factors such as:
Depending on these factors, your real-world migration performance may fluctuate significantly even within a single SharePoint installation. On the low end, you may only be able to move tens of MB per hour for sites with hundreds of lists with rich metadata, versions and permissions. On the higher end, moving up to 8-10 GB per hour of content-centric project and team sites with a highly optimized Migration Suite/Manager deployment is not unheard of. Different partitions of your SharePoint farm will fall somewhere between these extremes. The best way to understand where on the migration performance spectrum you are is to plan thoroughly by performing a series of test migrations, which need to include all types of sites.
The following document contains best practices and performance optimization tips that will let you get the best migration speed possible out of Migration Suite/Manager: http://en.community.dell.com/techcenter/sharepoint-for-all/m/downloads/20438273.aspx.