Motherboards are called the central circuits of a computer that bind all the parts of the computer together. It distributes all its power across the circuits, which then acts like a conduit, due to which the innards start working together.
Key Takeaways
- ATX (Advanced Technology eXtended) and Micro ATX are motherboard form factors, with ATX being larger and offering more expansion slots.
- Micro ATX is a smaller, more compact version of ATX, providing fewer expansion slots but maintaining compatibility with ATX cases and power supplies.
- Users should consider their requirements for the expansion and available space when choosing between ATX and Micro ATX motherboards.
ATX vs. Micro ATX
ATX is a motherboard form factor developed by Intel in 1995 and is commonly used in PC builds. It has specific measurements and features, including a 24-pin power connector, PCI and PCI Express slots, and support for multiple storage devices. Micro ATX is a smaller version of the ATX motherboard form factor.

The number of expansion ports located at the bottom end is more in the ATX format than the Micro ATX format, which is one of the downsides of the Micro ATX format.
This is a partial offset by most of the board manufacturers integrating common functions like networking, graphics, and sound. It is now common to see computers that no longer use expansion ports.
Comparison Table
Parameters of Comparison | ATX | Micro ATX |
---|---|---|
Size and dimensions | ATX board size is 305mm by 244mm. It is larger than Micro ATX. | Micro ATX board size is 61mm by 244mm. It is smaller than ATX. |
Shape | The ATX board is rectangular. | The Micro ATX board is square. |
Expansion slots | The ATX board has five expansion slots. | The Micro ATX board has three expansion slots. |
Drive bays | The number of drive bays in an ATX form factor is more than the Micro ATX form factor. | The number of drive bays in a Micro ATX form factor is less than the ATX form factor. |
Installation | An ATX board cannot be installed in a Micro ATX chassis. | A Micro ATX board can be installed in an ATX chassis. |
What is ATX?
The ATX format was developed in the year 1995. It is an enhanced AT model to ensure a more stable circuit. The ATX board is rectangular, 305mm by 244mm.
There have been many noticeable changes or upgrades to the newer models. For example, the ports in the newer models are arranged in such a way that they don’t overlap each other.
Also, the number of drive bays has increased in the new formats. This makes the number of drive bays more in the ATX form than in the Micro ATX form factor.

What is Micro ATX?
The Micro ATX format was developed in the year 1997. It is backward compatible with the design of the ATX. It is one of the newer formats developed after the ATX board’s development.
Many peripherals are integrated to deal with this problem of limited expansion slots. The ATX subsets are the mounting points of the Micro ATX format, and it uses the I/O panel.
The Micro ATX board will be an excellent choice for someone looking forward to building a gaming PC. It has enough RAM and free slots to ass any other PCIe expansion cards.

Main Differences Between ATX and Micro ATX
- The number of drive bays in an ATX form factor is more than in a Micro ATX form factor.
- A Micro ATX board can be installed in an ATX chassis, but the other way is not around is not possible.