Author: Delilah Daut
Saturday, November 30, 2019

What Is Form Factor on A Motherboard?

When talking about computers, the term 'motherboard' is highly likely to pop up on more than one occasion because it is vital. The primary function of the motherboard is to hold the microprocessor chip and give other parts the ability to connect to the microprocessor. Everything involved in the running or performance enhancement of a computer is plugged in via port or slot or is already part of the motherboard.

What Is Form Factor on A Motherboard?

The form factor is the layout and shape of a motherboard. It specifies the type of power supply and type of case that is supportable, the board's physical design and organization, and the location of mounting holes. If you are on a quest to assemble your own computer system, the form factor is an essential part that you need to pay attention to. But, first, you must purchase the correct case and components. 

Types of Form Factors

Baby AT and AT (Advanced Technology)

The AT and baby AT served as the most commonly used form factors during the early days of the computer. They come in different variations regarding width; the baby AT's are a little smaller in diameter, being 8.5" while the AT is 12" wide. 

  • AT: The AT form factor is mostly found in old machines because it is an outmoded factor. Among the IBM and IBM compatible computers, the AT form factor was commonly used. However, the width alone restricts its use when presented with smaller cases. In addition, a big section of the board overlaps with the drive bays, which makes upgrading, installation, and troubleshooting a challenge. 
  • Baby AT: The Baby AT has less width, which translates to minimal overlap. Therefore, it is an improvement of the AT. After its introduction, computer users stopped using AT and went for the economical and compact form factor. The baby AT is highly recognizable due to its full-sized keyboard connector and its shape. Unlike the AT, the Baby AT gives room for expansions and upgrades. The main challenges of using a Baby AT are: 
    • The expansion slots cannot accommodate long expansion cards 
    • The cases don't hold all mounting holes resulting in intermittent hitches.

ATX (Advanced Technology eXtended)

Intel introduced ATX, an advancement of the Baby AT. Currently, the ATX form factor is the most conventional motherboard design. However, the ATX is more advanced in terms of lower system cost, great support for future and current I/O, great support for processor technology, and easy use. The ATX form factor has been further diversified into micro ATX, nano-ITX, Mini-ITX, and flex ATX. The new designs have the same layout but keep minimizing the number of expansion slots and the size of the board. The specifications have been revised a couple of times, but the ATX design is still being used to date. The BTX (Balanced Technology eXtended) was supposed to replace the ATX though its development was discontinued. 

Enhancements of the ATX motherboard

"Soft Power" Support: The power supply of the ATX does not use a physical toggle switch. However, it is turned off and on using signals from the motherboard. Thus, a PC can be turned either off or under the control of software, giving room for better power management.  

Reduced drive bay interface: Given that the board is usually rotated 90 degrees compared to the baby AT style, the overlap between where the drives are and the board is significantly reduced, making access to the board easier. Moreover, this results in reduced cooling problems. 

Improved power supply connector: The baby AT form factor uses a pair of almost identical 6-pin connectors. However, the ATX employs a single 20-pin connector that is less confusing. 

3.3V power support: The ATX motherboard supports the 3.3v power from ATX power supplies. 

Upgradability: As part of the newest design, it is dubbed "the future's choice." More than that, due to more convenient access to the components on the motherboard, the design makes upgrading simpler.

Cohesive PS/2 mouse connector: The motherboard of the ATX has a built-in PS/2 port. 

Reduced expansion card interface: The memory sockets and processor slot are shifted to the back-right side just close to the power supply from the front of the board. Thus, the clearance issue with baby AT is eliminated, therefore giving room for full-length cards to be used in system bus slots. 

Micro ATX 

Its development came about as a naturally evolved form of the ATX form factor to tackle the new trends in PC technologies and markets. It supports:

  • Transitions to better processor technologies
  • Motherboards that are smaller in size
  • Form factors with lower power supply
  • Current technologies in processors
  • High-performance AGP graphics solutions

The Mini-ITX

It has a format of 6.7 x 6.7 inches and acts as a low-power consumption motherboard. The dimensions of the mini-ITX are the most distinguishing factor of this form factor. These types of motherboards were designed to empower low consumption teams. However, their benefits have grown in giant leaps, and there are no limits. 

Due to their open standard factor, the application mini-ITX has expanded in numerous kinds of applications. It is the first popularized standard system of reduced format. It acts as a standard format for all equipment, such as industrial applications, IoT (Internet of Things), and vehicle embedded computers. 


The Nano-ITX form factor, which measures 4.7" by 4.7", is a fully integrated board designed for low power consumption. As a result, it can be used in many applications. However, its design was specific to smart TVs, media centers, PVRs, and more smart entertainment. 


It is the smallest motherboard form factor in this list. It is 75% smaller than the Mini-ITX, measuring 3.9" by 2.8". The pico-ITX motherboard was developed and designed by VIA to bridge the gap for the innovation of smarter and smaller IoT devices. With a low-power consumption board and an x86-based-platform, the pico-ITX acts as an excellent choice for system applications that are embedded. These may include digital signage, industrial automation, in-vehicle computers, and more. 

Similarities among Mini-ITX, Micro-ATX, and ATX

They can support the same CPU: All three form factors possess the same CPU socket, given that they are from the same generation. So providing you are not going for high-end CPUs like Intel-E or overclocking, a mini-ITX can be able to give the same computing power as its cousin, the ATX. 

What Is Form Factor on A Motherboard?

Graphic cards: The three can run the same graphics cards if the graphics card can fit into the computer case and has a PCI-Express X 16 slot. Because high-end graphics cards are generally huge, most mini-ITX cases and some micro-ATX don’t have enough space for these motherboards. 

They have similar back panel ports: The space accommodated by connectors and rear panel ports on a motherboard is about the same no matter the size. The type of back panel ports and number receive influence from the price, instead. Therefore, an expensive board equals more and better ports. 

Some Applications of Form Factors

In-Vehicle Computers: Mini-ITX systems, due to their reduced format, are installed in the reduced spaces of vehicles to help in the monitoring of systems and real-time tracking. A good example is Lanner's V3G that is a fan-less and rugged vehicle computer. It is optimized for vehicle computing applications, and its processor consumes low power volumes and provides power upgrades. In addition, due to the evolution of wireless connectivity, the V3G offers swappable SIM slots that support cellular communications of 3G/4G and LTE. 

IoT devices: Multiple municipal governments have embraced smart LED street illumination as a foundation for various intelligent city establishments. Because the infrastructure of the streetlights already exists, city planners consolidate sensors, open-interface technologies, and wireless communication points to enable their IoT foundations to thrive in their smart lighting plans. 


Since millions of different embedded systems and IoT devices are on the rise, the motherboard's design is evolving at a very rapid pace. The adaptability of forms towards each application is improving as the sizes change. When building a computer or replacing a motherboard, obtaining a correct form factor is essential. In the process of an upgrade, consider being environmentally friendly. That is, select a board that uses a smaller form factor, integrated video, and one that is lead-free with low wattage. 

Creator Profile
Joined: 11/14/2019

ver: 20231031T141653