Micro-ATX, often referred to as mATX, or even mini-ATX, is a subset of the standard ATX form factor developed by Intel.
This form factor has seen several revisions since its debut in 1995 with more and more features being added with each release. A micro-ATX motherboard came as a later standard.
A Micro-ATX Motherboard Will Fit into a Case that Follows What Minimum Standard?
A micro-ATX motherboard will fit any case that follows the ATX 2.1 standard and above, making it the minimum standard.
The ATX 2.1 released in June 2002, is the oldest standard that supports theses micro form factors by default.
A MicroATX board is just a smaller, more compact version of the full-size form factor.
Therefore, any ATX case that can fit its motherboard will fit as a mATX case as well.
MicroATX Motherboard Vs Mini-ITX Motherboards
Both MicroATX motherboards and mini-ITX are derivatives of the full-size ATX motherboard standard.
They share the same mounting points which allow them to be cross-compatible with each other to a certain degree and can run the same CPU and power supply.
The MicroATX standard is one size smaller than full-size ATX boards while the mini-ITX board standard is one size smaller than MicroATX and two sizes smaller than standard ATX motherboards.
A MicroATX board measures in at 9.6 × 8.1 inches, whereas the mini-ITX standard is 6.7 × 6.7 inches.
What Is Included in the Motherboard Form Factors?
mATX Form Factor
Micro form factor boards come with up to 4 PCIe slots, usually 2, but sometimes 4, memory slots and one M.2 slot. Somemodern mATX boards also include a second M.2 slot.
mini-ITX Form Factor
Mini-ITX is a lot more restricted comparatively. It can only include 1 PCIe slot and 2 memory slots.
Plus, there is literally no space on the PCB for a second M.2 slot, so it just has one.
There are also small differences in power connector options, options for cables, and overall cooling performance.
Will A Micro-ATX Motherboard Fit into a Case for an ATX?
A Micro-ATX Motherboard will fit into an ATX Case. An ATX case come with a lot of mounting holes, 9 of which are outfitted with standoffs.
These nine are used by full-size motherboards with this form factor. Whereas, usually, only 8 of them are needed to connect the pins of MicroATX boards.
Micro-ATX Case and Motherboards Backward Compatibility
The Micro ATX spec was explicitly designed to be backward compatible with ATX.
The mounting points used in the mATX spec are a subset of those used in full-size ATX cases which enables them to be backward compatible.
That’s why any PC cases that are designed to fit ATX boards should also support MicroATX and mini-ITX motherboards without any modding necessary. This is true for Intel and AMD motherboards.
The ATX standard has gone through many updates since its inception in the 90s. From graphics card updates to better cooling for all your computer parts, this form factor is truly that one to live up to. ATX remains the de facto standard for computers manufacturers to follow.
What Cases Will a MATX Motherboards Fit Into?
Any computer case designed with a full-size ATX spec should fit a mATX motherboard. Some SFF cases are also compatible with MicroATX boards but they likely won’t take a full-sized power supply.
Can a MicroATX Fit in a Mid Tower case?
Mid-tower Cases are designed to fit both standard ATX and every other form factor standard below it, which includes MicroATX. So a Micro-ATX motherboard will fit a mid-tower case.
Can a MicroATX Fit in a Full Tower?
Full tower cases are generally meant for larger builds that use Extended ATX components. But, modern, maximum size tower cases should easily fit micro-ATX motherboards because the mounting points are positioned identically.