CPU cards and modules are computer boards that contain the central processing unit (CPU) of a computer. A CPU module is a connectorized CPU with the external logic required to allow it to function. CPU cards and modules are specified by CPU speed and bus type as well as other features and applications built in to the card.
CPU cards and modules include peripheral component interconnect (PCI) cards, modular PC/104 cards, industry standard architecture (ISA) cards, PCI extensions for instrumentation (PXI) cards, embedded technology extended (ETX) cards, and many others. CPU cards and modules are often used to expand the memory, speed, bandwidth, or embedded applications of an existing computer system. PCI cards offer high speed and wide bandwidth functionality. PC/104 cards are typically used to expand a system’s embedded applications. PC/104 cards include modules for audio and video applications, data communications, and embedded storage. PXI cards are used for data acquisition and control systems, making them suitable for real-time measurement applications. ETX cards are used in industrial applications to augment a computer system’s embedded applications. ETX cards contains all the functionality necessary to run the PC in a compact space.
CPU cards and modules that are used to augment existing computer backplanes typically have ISA or PCI connectors, and can be plugged into the backplane without any additional configuration. CPU cards and modules for use in computer backplanes are typically half-sized. Backplanes are different from computer motherboards in that a backplane contains no processing power or logic of its own. The CPU card contains the PC functionality and communicates with the other cards plugged into the backplane through a computer bus. CPU cards and modules may also be called expansion cards or expansion boards, and offer a variety of embedded applications from modems and wireless networking to graphics and video controllers to RAID controllers. RAID is an acronym for redundant array of independent disks.