Concept
In computing, the motherboard form factor is the specification of a motherboard – the dimensions, power supply type, location of mounting holes, number of ports on the back panel, etc. Specifically, in the IBM PC compatible industry, standard form factors ensure that parts are interchangeable across competing vendors and generations of technology, while in enterprise computing, form factors ensure that server modules fit into existing rackmount systems. Traditionally, the most significant specification is for that of the motherboard, which generally dictates the overall size of the case. Small form factors have been developed and implemented. A PC motherboard is the main circuit board within a typical desktop computer, laptop or server. Its main functions are as follows: To serve as a central backbone to which all other modular parts such as CPU, RAM, and hard drives can be attached as required to create a computer To be interchangeable (in most cases) with different components (in particular CPU and expansion cards) for the purposes of customization and upgrading To distribute power to other circuit boards To electronically co-ordinate and interface the operation of the components As new generations of components have been developed, the standards of motherboards have changed too. For example, the introduction of AGP and, more recently, PCI Express have influenced motherboard design. However, the standardized size and layout of motherboards have changed much more slowly and are controlled by their own standards. The list of components required on a motherboard changes far more slowly than the components themselves. For example, north bridge microchips have changed many times since their introduction with many manufacturers bringing out their own versions, but in terms of form factor standards, provisions for north bridges have remained fairly static for many years. Although it is a slower process, form factors do evolve regularly in response to changing demands.
