The architecture of the Intel QuickPath Interconnect (Intel QPI), like many components in a computer system, is comprised of a number layers. Each of these layers performs a distinct function in controlling the logical operation of the Intel QPI. This article introduces the four architectural layers of the Intel QPI—the physical, link, routing, protocol layers—and then introduces other aspects of the architecture including performance and reliability, as well as some initial design considerations for a system using Intel QPI.