The AD RMS team has recently published new content that details best practices for properly scaling and managing your AD RMS infrastructure.
The following abstract details the contents of this documentation:
Here we describe the scaling scheme for an AD RMS infrastructure, we define sizing parameters for the server roles in an AD RMS infrastructure, and we describe logging characteristics of AD RMS that enable adequate performance monitoring. We also present real-world data regarding Microsoft’s own production implementation of AD RMS in order to enable you to perform preliminary sizing estimates for your own infrastructure.
We hope these guidelines prove to be helpful to you as you configure your AD RMS environment.