Motherboards - Form Factor

A recent Tech Tip covered the basics of choosing a computer case & made mention of the various sizes that correspond to motherboards of different form factors. A few people wrote in expressing interest in understanding more about the basics of motherboards, & that is exactly what this Tech Tip intends to address.

A motherboard, often known as a main board, is the primary circuit board inside of a computer, & is where the central processing unit (CPU), memory, expansion slots, drives, & other peripheral devices are connected. The circuitry on a motherboard facilitates the communication between all of the devices in the computer, making them as critical to a system's performance as items such as the CPU or memory.

The core circuitry of a motherboard is often called its chipset, & usually the manufacturer of the motherboard is not the manufacturer of the chipset. Intel does produce motherboards with their own chipsets, but purchasing a motherboard brand such as Gigabyte, Biostar, & ASUS means getting a board with either a VIA, Nvidia, SIS, or Intel brand chipset.

. Form Factor

The different basic shapes & sizes of motherboards are categorized as form factors. There are several standard form factors obtainable, but a lot of the more common ones present in desktop computers include:

(http://www.formfactors.org/developer/specs/atx2_2.pdf), ATX (http://www.formfactors.org/developer/specs/matxspe1.2.pdf), Micro ATX (mATX) (http://www.formfactors.org/developer/specs/FlexATXaddn1_0.pdf) FlexATX (http://www.via.com.tw/en/initiatives/spearhead/mini-itx/) & Mini-ITX

The basic sizes of each are as follows:

* ATX: 12" x 9.6" (305mm x 244mm)

* Micro ATX: 9.6" x 9.6" (244mm x 244mm)

* FlexATX: 9.0" x 7.5" (229mm x 191mm)

* Mini ITX: 6.7" x 6.7" (170mm x 170mm)

ATX & mATX are by far the most popular motherboard sizes for desktop computers, & as seen in the list above, are & a lot of the largest. More actual estate on a motherboard allows for greater expansion possibilities & additional features, which make the use of these boards more flexible. A Mini-ITX board may feature slot for memory & slot for an expansion card, while a typical ATX board may feature memory slots & slots for expansion cards.

Each form factor has its own niche that it fits in to, from workstations & betting systems for larger boards to media centers & in-car computers for smaller boards. There is definitely overlap between the potential applications of each form factor, & other features & capabilities will also influence the targeted use.