Hi,
Check the below link for the Hardware requirements for SQL Server 2008, which is also same for Analysis Services:
http://blog.sqlauthority.com/2008/09/02/sql-server-hardware-and-software-requirements-for-installing-sql-server-2008/
Requirements and Considerations for Analysis Services Deployment:
http://msdn.microsoft.com/en-us/library/ms175672.aspx
Bye.