http://blogs.technet.com/aqa/archive/2008/01/07/architecture-talk-sharepoint-farms.aspxMicrosoft Office SharePoint Server 2007 is highly scalable in both directions: vertical and horizontal.  The support for 64-bit architecture, multi-CPU/multi-core hardware, and large amounts of memory makes it possible to scale up boxes running SharePointen-USCommunityServer 2.1 SP1 (Build: 61025.2)