This paper presents the key decision points, architecture design and definition, and test criteria and results from a scalability and performance test conducted at the Microsoft Partner Solutions Center (MPSC) in Redmond, Washington. It is intended to provide strategic information about designing a high-volume, high-availability enterprise solution that can easily grow.
Great whitepaper - http://go.microsoft.com/fwlink/?LinkId=120881&clcid=0x409