mATX

MicroATX, often abbreviated as mATX, is a motherboard form factor that measures 244 x 244 mm (9.6 x 9.6 inches). It was developed to provide a smaller yet compatible alternative to the standard ATX while retaining many features used in desktop systems. MicroATX boards use the same CPU sockets and memory technologies as ATX boards and share the same mounting holes and I/O shield, allowing them to fit in many ATX and microATX cases and to be powered by standard ATX power supplies.

A defining characteristic of microATX is its balance between size, expandability, and cost. Most microATX boards offer four RAM slots and up to four PCIe expansion slots, though the number of PCIe x16 slots varies and is typically one or two, with additional smaller PCIe x1 slots. This makes them suitable for mid-range builds with a discrete graphics card, multiple storage devices, and peripherals, while avoiding some of the higher cost and larger footprint of full-size ATX boards.

Storage and networking options on microATX boards are similar to larger boards, often including multiple SATA ports and one or more M.2 slots for NVMe drives. Networking commonly includes onboard Ethernet, with some models adding Wi‑Fi. Overclocking support depends on the chipset and board design, with higher-end microATX boards providing more robust features for tuning performance.

MicroATX is popular for budget and compact desktop builds, offering a smaller footprint without sacrificing essential expansion and compatibility with a wide range of components.