Motherboards come in different sizes and variations according to their use in different types of computers. The motherboard is a vital computer component that houses and delivers the required amount of power to every other component in your computer. A motherboard is an integrated circuit embedded with sophisticated connections, buses, and ports compatible with various other components commonly used in computers to serve different purposes. Today we are going to shed some light on motherboard sizes and which form factor is best for you. 

It can accommodate every other device your computer needs to execute different tasks. Processors, Graphics cards, Audio devices, USBs, Hard drives, Solid state drives, etc., all connect to the motherboard in one way or another to deliver their pre-ordained functions. So, to answer the question, No, All motherboards are not the same size.

As computers are shrinking and their uses have expanded into every aspect of life, motherboards have also been accordingly made to accommodate their smaller components. For example, Smartphones also have a motherboard, processor, RAM, etc. As smartphones are being reduced in size to be more mobile, lighter, and thinner, their inner parts are also being designed to be much smaller than before, so they can effectively fit in that smartphone body.

There are a lot of motherboard options in today’s computing landscape, and their variations are mainly based on their size and processor compatibility. In this article, I will explain the numerous form factors of motherboards used in PC building and what type of motherboard is a good choice for you.

Motherboard Sizes Explained

As mentioned earlier, there are a lot of motherboard form factors or sizes that are available. When building a gaming PC or a computer for general use, having a pet idea of what form factor motherboard to buy for your processor is of utmost importance. Different form factor motherboards offer different features, and as common sense dictates, a big motherboard will have more features than a small one, but that isn’t necessarily the case if you compare motherboards of two different generations.

Form factors are used to define the dimensions of a motherboard, and these form factors are designated in specific letters with suffixes like “Micro or Mini.” However, their designations are still not easily understandable if you are new to the world of PC building. With this article, you will get the exact meaning of these form factors and what type of motherboard they are used to symbolize.

ATX Motherboard

The first and most common motherboard form factor to discuss is ATX. These motherboards measure around 12 × 9.6 inches and fit perfectly in an ATX PC case. The PC case that can fit these motherboards should be ATX compatible regardless of whether they are Full-tower, Mid-tower, or Mini-tower; as long as they are made to accommodate ATX motherboards, the fitting will be accurate. They are suitable for overclocking processors and GPUs as they are powered by 24-pin connectors and use 6/8-pin connectors for CPU and GPU.

ATX motherboards are usually full-sized motherboards with four or more than four DIMM RAM slots. Because of their sheer size, these motherboards also have many USB ports and incorporate an I/O panel and, a good-quality, metallic shield. Moreover, they also support Dual-Channel memory for faster and better memory performance. They can afford up to four graphics cards with the help of AMD Crossfire or Nvidia SLI, which enables the syncing of multi-GPU systems.

Also, they commonly have many SATA ports, WiFi, Bluetooth, Expansion slots, and high-quality sound cards to deliver the ultimate computing and gaming experience. The adequately large size is perfect for installing efficient and big heat sinks and CPU coolers to bring effective thermal stability to your system. Depending on the manufacturer, these motherboards can also have premium heat sinks pre-installed onto the motherboard, and some are specifically designed for gaming PCs with excellent airflow and heat dissipation.


  1. Feature complete I/O panels
  2. Better heat dissipation and thermal stability
  3. Mostly unlocked for overclocking
  4. High-quality Voltage Regulator Modules


  1. Not for Compact builds
  2. Costly compared to other motherboards

Micro ATX Motherboard

MicroATX or mATX motherboard is another prevalent form factor that is used for PC builds nowadays. This form factor is smaller than the standard ATX motherboard and includes fewer features. They are square-shaped with equal side-to-length dimensions of around 9.6 × 9.6 inches. These motherboards are made for relatively compact PC cases, offering similarly powerful attributes to ATX.

The size limits these motherboards' potential and expansion slots, but they can still be enough to build a powerful gaming rig. They usually have two to four DIMM RAM slots that use Dual-Channel memory and can support up to 64 Gigs of RAM, which is overkill even for modern computing standards. They also can have up to four PCIe Expansion slots capable of accommodating multiple graphics cards to create an ultimate gaming or creative machine. Their features and support systems are similar to ATX, but the overall size of the motherboard gets a lot smaller in comparison. These motherboards also incorporate good VRMs and WiFi/Bluetooth with many other features similar to the ATX motherboards. But smaller size has caveats, as you might get fewer USB and SATA ports.

ATX builds require much more room and space and can usually fit on a single table with a monitor and other computer accessories and peripherals. MicroATX builds, however, are great for smaller spaces as they require too many length or height considerations in their spacing. Many experienced manufacturers offer both ATX and mATX motherboards, and it is up to the user’s preference on which one to buy.


  1. Smaller in size than ATX but has identical features
  2. Perfect for Compact cases
  3. Premium Build Quality
  4. Good heat dissipation


  1. Not efficient for overclocking
  2. Insufficient power delivery

Mini ITX Motherboard

Mini-ITX form factor motherboards are the smallest PC motherboards with dimensions of 6.7 × 6.7 inches and are also square-shaped. The mini-ITX boards are made for very compact PC builds, usually for horizontal cases, for light and daily tasking. These motherboards have enough features to make a full-fledged PC, but their tiny size warrants many compromises, limiting their usage. Mini-ITX motherboard-based PCs are more commonly used for office work and in corporate culture, which only requires computers capable of running light to decent tasks.

These motherboards have only two DIMM RAM slots and support around 16 Gigs of memory. It has a single PCIe Expansion slot that can be fitted with a good graphics card, but Mini-ITX PC cases have notoriously less space to install a gaming GPU. However, you can still install a powerful processor onto this motherboard that doesn’t exceed this board’s power output. Still, you won’t be able to overclock or fully push that CPU because the cooling and VRM on these motherboards aren’t very efficient for such tasks.


  1. Highly compact size, great for building a small PC


  1. I/O options are a few
  2. Power delivery isn’t great

E-ATX Motherboard

Extended ATX or EATX motherboards are broader and wider siblings of the Standard ATX motherboard and have 12 × 13 inches dimensions. These motherboards are made for PC enthusiasts and for building PCs that can handle the heaviest computational loads. They aren’t specifically made for gaming but enable you to build a performance-heavy gaming rig.

They are usually for computers that tackle heavier tasks requiring higher processing power, RAM, Memory, and graphical computation. A perfect example of such tasks is the engineering simulations which require every bit of graphical power and RAM you can spare. At times the motherboards come with dual processor sockets so that you can simultaneously utilize the power of two processors in use cases where they are required. Moreover, They have up to 8x DIMM RAM slots with 4x PCIe x16 slots, enabling users to install unfathomable amounts of RAM and GPUs.


  1. Dual Processor Socket support
  2. More connectors than an ATX motherboard
  3. More RAM slots
  4. A higher number of PCIe x16 slots


  1. Very costly without the addition of any unique features
  2. Can’t fit in typical PC cases
  3. Limited products

XL ATX Motherboard

With dimensions of 13.6 × 10.4 Inches, these motherboards don’t abide by the average size standards. If you thought the E-ATX motherboards were overkill, these would surprise you. These motherboards have features similar to the E-ATX but have some added ports and slots without providing any further value. They have up to 8x DIMM RAM slots and have more connector ports than any other motherboard.

XL-ATX motherboards have minimal usage and have been going extinct because their sheer size is problematic, and finding its compatible PC case is a pain. Moreover, as processors become increasingly powerful, the concept of a motherboard with a dual-processor socket feels redundant, as modern processors hold enough power and cores to wrangle any task without a problem.


  1. Supports more memory and connectivity


  1. Extremely Expensive without any real value for money
  2. Rare usage and availability
  3. Don’t fit in even the largest PC cases

How to Choose a Motherboard

So which form factors should be the best for you? Well, it depends on several factors, which include your preference, processor, requirement, and budget.

Motherboard Form Factors

Your preference for a motherboard is whether you want to buy a compact one that can go easily into a smaller PC case and be placed onto your computer table without looking too big or wrong, or you want to build an Ultimate gaming PC that doesn’t compromise on anything and has all features and latest tech available to it so that you can upgrade its parts in the future. 

For the first option, you can choose the MicroATX motherboards because they are competent boards that can hold onto your PC components and be part of a robust and decent mid-end gaming build. For the second option, it would be wise to go with a modern Standard ATX motherboard, as they have all the requisite features and can accommodate high-end processors and graphics cards. If you aren’t too worried about the size of your PC, then ATX motherboards are a no-brainer.

CPU and Chipset

Intel and AMD have different types of sockets on their processors, and it is essential to buy the motherboard with the same socket support as your processor; otherwise, your processor won’t work at all. Most modern AMD processors use the socket type of AM3 to AM5, depending on the power and cores of the processor. For mainstream AMD processors, you can use both ATX and Micro ATX motherboards which support AMX sockets and deliver optimal power. A series of motherboards that support AMX sockets are A300 to A500, B500, and X500.

Similarly, Intel processors use LGA sockets with different designations, which can vary depending on the generation of the processor. A series of modern motherboards that support LGA sockets are; Z400 to Z700, B500, and B600.

Motherboard Prices

Micro ATX motherboards are usually considered a budget pick. If you have a mid-end processor and don’t want to spend too much on a motherboard, then Micro ATX motherboards are the best choice. Their lower price is due to their smaller size and fewer features, such as a smaller number of ports, RAM slots, and only mediocre cooling options.

However, if you don’t have a budget constraint, you can buy a good quality ATX motherboard for building a mid to high-end PC with all the features like the latest USB connectivity options, WiFi, etc. They can accommodate bigger and better coolers and fans for the thermal stability of your PC.


An ATX motherboard has all the specifications and attributes that a PC builder requires. They have more RAM and PCIe Expansion slots, USB ports, WiFi, Good to Excellent Sound Cards, and are overall better equipped for efficient cooling than a MicroATX motherboard.

Hence, if you require a motherboard with more than enough everything, buy an ATX. But if you are willing to compromise on some of your requirements or don’t have that many prerequisites, then MicroATX motherboards will serve you just fine.

Frequently Asked Questions

Which motherboard has the smallest Form Factor?

Mini-ITX motherboards have the smallest form factor. Although laptop motherboards can get even smaller than a Mini-ITX, in Personal Computers, Mini-ITX motherboards are the smallest mainstream motherboards.

Which motherboard form factor is the most common?

ATX form factor is the most common form factor in motherboards and is the widely used motherboard standard worldwide. Many respected manufacturers have many products based on this form factor, and their prices can vary according to the features they are embedded with.

Are there any compatibility issues regarding motherboard sizes?

Yes, there can be a compatibility issue regarding the motherboard size with your PC case. If your PC case isn’t made to fit a specific type of motherboard, then you will have a hard time fitting that motherboard into that case. Moreover, a compact case made for a low-form factor motherboard cannot accommodate great cooling options because of its limited space.

Zain Ali
Zain is a gamer who turned into a tech enthusiast the day he got his first PC. He loves to play with whatever components he can get his hands on. His love for custom PC hardware is unfathomable, and he keeps it alive by writing about it as well as doing practicals in real life along with the continuation of his degree in business administration.