Plan Your Server Farm with Capacity Management Resource Center for SharePoint 2010

The release of SharePoint 2010 Products marks a substantial change in the way Microsoft approaches capacity and performance documentation. We have listened to feedback and learned from customer experiences with SharePoint Server 2007 and our own testing to establish a comprehensive set of initial guidance for capacity and performance management for SharePoint 2010.

https://blogs.msdn.com/sharepoint/archive/2010/05/06/plan-your-server-farm-with-capacity-management-resource-center-for-sharepoint-2010.aspx