Once you're sure that your cube design is as good as you can make it, it's time to look at two features of Analysis Services that are transparent to the end user, but have an important impact on performance and scalability: measure group partitioning and aggregations. Both of these features relate to the Storage Engine and allow it to answer requests for data from the Formula Engine more efficiently.
A partition is a data structure that holds some or all of the data held in a measure group. When you create a measure group, by default that measure group contains a single partition that contains all of the data. Enterprise Edition and BI Edition of Analysis Services allow you to divide a measure group into multiple partitions; Standard Edition is limited to one partition per measure group, and the ability to partition is one of the main reasons why you would want to use Enterprise Edition or BI Edition over Standard Edition.