Energy-Efficient Computing and Data Centers

1Systems in Data Centers

There are different types of IT equipment that serve different functions depending on customer application. This chapter provides an overview of servers, storage arrays, switches and their components.

1.1. Servers

A server is a broad term describing a specific piece of IT equipment that provides computing capability and runs software applications in an environment networked with other IT equipment, including other servers. Most servers contain the following major hardware building blocks: processors, memory, chipset, input/output (I/O) devices, storage, peripherals, voltage regulators (VRs), power supplies and cooling systems. Additional application-specific integrated circuits (ASICs) may be necessary, such as an onboard redundant array of independent disks (RAID) controller and a server management controller.

Volume rack-mounted servers are designed to fit within commonly available rack sizes, such as the 19 in. (0.5 m) rack form factor defined by EIA/ECA Standard 310-E specification¹. The vertical dimension is expressed in terms of rack units or just units (U). One U or 1U represents 1.75 in. (44.45 mm) of vertical height within a rack. Servers used for computing are available in standard rack-mount and custom configurations. Typical dimensions and sizes for standard rack-mount compute servers are full-width 1U, 2U or 4U. A single-server chassis may contain multiple server nodes. Each node is defined as containing all key components, except power ...