Difference Between ATX and Micro ATX

ATX and Micro ATX are two common motherboard form factors found in modern computers. The primary difference between these two form factors is their size and number of expansion slots.

ATX stands for Advanced Technology Extended and refers to a larger motherboard form factor that measures 305mm by 244mm. It usually has more expansion slots than Micro ATX, making it ideal for high-end gaming and workstation builds. ATX motherboards typically have up to seven expansion slots, which include PCI, PCIe x1, PCIe x4, and PCIe x16 slots, allowing users to add multiple graphics cards, sound cards, network adapters, and other expansion cards.

Micro ATX also known as mATX. It is a smaller motherboard form factor that measures 244mm by 244mm. It usually has fewer expansion slots than ATX, usually up to four, including PCI, PCIe x1, and PCIe x16 slots. As a result, it is appropriate for compact desktop builds, low-cost builds, or applications that do not require a large number of expansion cards.

Read this article to find out more about ATX and Micro ATX and how they are different from each other.

What is ATX?

ATX which stands for Advanced Technology eXtended is a motherboard form factor introduced by Intel in 1995. It is a standard specification for the physical layout and design of personal computer motherboards, and it has since become the most popular motherboard form factor for consumer desktop PCs.

ATX is the standard form factor for the industries. When larger cases are available, ATX motherboards have more options. In the case of a larger case, it opens the door to additional advanced options such as SLI or tri-SLI. Additional ports, such as USB, PCI, and SATA slots, can be included on full-size ATX motherboards.

The position of the power supply fan is an additional feature of the ATX motherboard. To improve cooling and reduce noise, air is blown directly onto the processor and expansion cards.

What is Micro ATX?

Micro ATX is a smaller motherboard form factor that offers a more compact alternative to the larger ATX form factor. Despite having fewer expansion slots and components, they are still appropriate for budget builds, HTPCs, and compact desktops. Because of their smaller size, they are more energy-efficient and suitable for low-power builds, but their performance in high-end builds may be limited.

Micro ATX supports only two RAM slots, but ATX supports four RAM slots. Due to more energy-efficient, they are suitable for low-power builds and HTPCs. Micro ATX motherboards are less expensive compared to ATX motherboards.

One disadvantage of Micro ATX motherboards is the limited space available for components and cooling solutions. They have smaller heatsinks and fewer fan headers than ATX motherboards, limiting their performance in high-end builds. They also have a smaller I/O shield, which can limit the number of available ports and connectors.

Difference between ATX and Micro ATX

The following table highlights the major differences between ATX and Micro ATX −



Micro ATX


The size of the ATX is 305 mm by 244 mm.

The size of the Micro ATX is 244 mm by 244 mm.

Slots Expansion

The slots can be expanded up to seven.

The slots can be expanded up to four.


High Cost

Low Cost


It has more cooling space compared to Micro ATX.

It has the less cooling space


The primary distinction between ATX and Micro ATX is their size and number of expansion slots. The decision to choose between the ATX and Micro ATX is completely depends on the user's requirement and their budget. The ATX motherboard is best option for those who requires the more expansion slots and have the good budget. Whereas the Micro ATX is best option for those who requires a less expansion slots and have the limited budget.

Updated on: 03-Apr-2023

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