Atx motherboard

The ATX motherboard standard is the subject of this article. Each motherboard size is introduced, such as e-atx (extended ATX), miniatx, xl-atx, and so on. The brain of a personal computer, consisting of a complicated electronic circuit board and motherboard. There are various different types of motherboards, each with its own size.

People who buy pre-built PCs may not be aware of this, but those who build their own PCs should be aware of the motherboard standard. Let me begin by introducing you to ATX, the most widely used standard.

What is the ATX Motherboard Standard?

What is the ATX Motherboard Standard?

One of the architectural standards for personal computers is ATX. ATX stands for Advanced Technology extended.

Intel developed and announced it in 1995 as a single motherboard standard.

The form factor is a structural specification for computer components.

By providing a standardized form factor, parts can be replaced.

Among these form factors, the one that has been used for a long time is the shape standard of the motherboard.

And ATX is the mainstream form factor for motherboards.

A motherboard that meets the standards is used for the PC case, which is the main body of the PC.

ATX has a maximum vertical size of 244 mm and a maximum horizontal size of 305 mm.
It is mainly used for large PCs such as full towers and middle towers, and also supports mid-range to high-performance high-end models.

With high support from gaming PC users, ATX can be said to be the standard for motherboards.

There are up to 7 expansion slots, and 4 to 8 memory slots are attractive for high expandability.

A large graphic board can be mounted, many SATA terminals are also mounted, functions such as a CPU power supply circuit that supports high loads are also mounted, and there are various good points due to the large area.

What is the Micro-ATX motherboard standard?

What is the Micro-ATX motherboard standard?

Micro-ATX and Mini-ITX are also popular and widely distributed form factors like ATX.

Let’s start with Micro-ATX.

Micro-ATX is a tiny version of ATX, measuring up to 244mm x 244mm. Consider a rectangle ATX to be the same size as a square.

As a relatively small PC motherboard, it is often used in space-saving desktops and mini towers.

Many home-built PCs have excellent cost performance, and can be said to be mainly for the middle range. It is also suitable for the first time you try to make your own.

The maximum number of expansion slots is 4, and the number of memory slots is 2-4, which is about half the expandability of ATX motherboards.

Although it is a balance with the case size, the size of the motherboard is smaller than ATX, but a large graphic board can also be mounted.

Micro-ATX Motherboard List

What is the Mini-ITX motherboard standard?

What is the Mini-ITX motherboard standard?

Next, 170mm x 170mm size Mini-ITX.
It is the smallest of the three mainstream standards.
A form factor developed by a Taiwanese company, the series also includes smaller Nano-ITX and Pico-ITX.
Mini-ITX was designed for use in embedded systems.
Therefore, the expansion slot is one and the expand ability is low, and it is suitable for ultra-small personal computers.
Recently, the number of companies selling Mini-ITX size motherboards has increased, and the performance of parts has improved, making it possible to create high-performance BTO personal computers and home-built personal computers.
Therefore, it is attracting attention not only as a low-cost sub-machine but also for various purposes such as creating ultra-small game machines.

Mini-ITX Motherboard List

In addition, personal computers made by major manufacturers tend to develop their own motherboards based on these mainstream motherboards such as ATX.

Support between Intel CPU motherboards and AMD CPU motherboards

To replace the CPU, it is necessary to support the chipset and socket mounted on the motherboard.
Chipsets are manufactured as a set by Intel and AMD, which are companies that design and manufacture CPUs.
The socket refers to the shape (number of pins) that connects the CPU and the motherboard, and is largely determined by the chipset.
Chipsets and sockets have the same combination except for some special motherboards.
Therefore, it is possible to search for a compatible CPU from the chipset (socket) of the PC to be replaced.

The following table shows the links of the corresponding CPU sockets and compatible motherboards.
Please check it out.

Please check it out.

socketMain supported CPUTower compatibleMini tower compatibleSlim compatible
LGA 2066
(Cascade Lake)Core i9 10920X etc.
LGA 1200
(Rocket Lake)Core i7 11700K etc.
LGA 1200
(Comet Lake)Core i7-10700K etc.
LGA 1151
(Coffee Lake)Core i7-9700 etc.
LGA 1151
(Kaby Lake / Skylake)Core i7-7700, 6700, etc.
LGA 1150
(Broadwell / Haswell)Core i7-5775C, 4770, etc.
socket Main supported CPUTower compatibleMini tower compatibleSlim compatible
Socket sWRX8
(Ryzen Threadripper)
Socket AM4
Introducing Intel CPUs and AMD CPUs that support motherboard sockets

Here are some of the links to the list page of Intel CPUs and AMD CPUs that correspond to the CPU sockets of each motherboard.
You may want to consider purchasing or replacing the motherboard and CPU as a set.

LGA 2066 (Cascade Lake) CPU list

LGA1200 (Rocket Lake) CPU list

LGA1200 (Comet Lake) CPU list

Socket sWRX8 (Ryzen Threadripper) CPU list

Socket AM4 (Ryzen) CPU list

What are motherboard standards such as “Flex-ATX”, “Extended-ATX” and “XL-ATX”?

There are also other form factors that are considered minor standards.
Flex-ATX is a smaller standard of Micro-ATX.
The board size is 244 mm x 191 mm, and it is used for cube-type and bookshelf-type space-saving personal computers.
Although products that use FlexATX are shipped mainly by manufacturers, it cannot be said that the slimming of the case is prioritized and the specifications are being standardized.
It’s useful in environments where space savings are essential, but it’s less extensible.

On the contrary, there is also a standard that increases the size of ATX.
Extended-ATX has a large board size of 305 mm x 330 mm, has a large memory capacity, and has plenty of slots.
It is used for gamers and workstations rather than for general personal computers, and is also used for multiprocessor servers with many mounting parts.

The size of XL-ATX is 325mm x 244mm, which is a standard that stretches ATX horizontally.
XL-ATX compatible motherboards are equipped with 7 PCI Express x16 expansion slots, and some models support up to 4 Way SLI / CrossFireX, which is configured to support powerful multi-GPU.

Motherboard standard size comparison

Based on the contents so far, the comparison of the standard size (size) of each motherboard is summarized in the table.

 Size (size)
ATX motherboard244 mm x 305 mm
Micro-ATX motherboard244 mm x 244 mm
Mini-ITX motherboard170mm x 170mm
Flex-ATX Motherboard244 mm x 191 mm
Extended-ATX Motherboard305 mm x 330 mm
XL-ATX motherboard325 mm x 244 mm


Each standard specifies the dimensions of the motherboard and the maximum CPU that can be supported. “ATX,” “Micro-ATX,” and “Mini-ITX” are the most common form factors for home-built computers.

It will be a compromise with the size of the PC case, but it is a good idea to think about and choose it carefully while considering the configuration of the CPU and graphics board you want to use.


* Celeron, Intel, Intel, Intel logo, Intel Atom, Intel Core, Intel Inside, Intel Inside logo, and Pentium are trademarks of Intel Corporation or its subsidiaries in the United States and / or other countries.

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