CPU card
A CPU card is a printed circuit board (PCB) that contains the central processing unit (CPU) of a computer. CPU cards are specified by CPU clock frequency and bus type as well as other features and applications built into the card.
CPU cards include peripheral component interconnect (PCI) cards, modular PC Cards, Industry Standard Architecture (ISA) cards, PCI extensions for instrumentation (PXI) cards, embedded technology extended (ETX) cards, and many others. CPU cards are often used to expand the memory, speed, bandwidth, or embedded applications of an existing computer system. PC cards are typically used to expand a system’s embedded applications. PC 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 contain all the functionality necessary to run the PC in a compact space.