As ISV's began to think about designing "multi-tenancy" into their products, they often struggle with what the performance implications will be of the various design choices they face in making multi-tenancy a reality.

There is an architecture team at Microsoft that is completely focused on this space, and they have released an update to their architectural reference application (Litware HR) that not only shows some example implementations of solutions in this space, but also includes results from a round of performance testing they did to explore the performance trade-offs of several common approaches.

Hope that clears some of the S+S fog away for you…