While not long ago systems had only several serial links, it’s now becoming common for systems to include hundreds—and even thousands—of such links. This paper describes the development and analysis of a large system with thousands of serial links. Due to the system’s size and complexity, the design team invested in a multi-year effort to build and qualify a virtual environment capable of both verifying connectivity and simulating any and all of the channels. Problematic channels with incomplete system-level connections, poor eye openings, or high BER are quickly identified.