The IBM eServer xSeries 455 is the second-generation Enterprise X-Architecture server using the 64-bit IBM XA-64 chipset and the Intel Itanium 2 processor. Unlike the x450, its predecessor, the x455 supports the merging of four server chassis to form a single 16-way image, providing even greater expandability and investment protection. This IBM Redbooks publication is a comprehensive resource on the technical aspects of the server, and is divided into five key subject areas: --Chapter 1, “Technical description”, introduces the server and its subsystems and describes the key features and how they work.