ATX vs MicroATX vs Mini-ITX: What's the Difference?

Motherboards are a vital part of a PC, and one of the parts you should decide on first. The type of motherboard you pick will decide what cases you can choose, your storage configuration, how many sticks of RAM you can have, and much more.

So, given the important of the motherboard, and the less-than clear names that designate the sizes, we thought we'd explain all for you today.

The two most common options are ATX and MicroATX, but Mini-ITX is becoming increasingly popular due to its compactness. They can determine a few important factors regarding the appearance, usability, and overall capabilities of your PC's components.

Custom gaming PCs are divided into SFF, MicroATX, and ATX, each offering different hardware options and designs. But what makes them different? And which one should you choose when building your new PC?

The Advanced Technology Extended form factor, or ATX, is the name of a specific motherboard and power supply specification that, when it was introduced in 1995, took older designs and created a more uniform, higher performance standard for the industry.

Today, it remains the most popular motherboard size and the typical basis for modern computers, whether gaming PCs or work machines.

A standard ATX motherboard measures 305 x 244 mm and typically includes:

• - Four RAM slots
• - Multiple PCI-E x16 slots, supplemented by PCIe x4 and x1 slots
• - A handful of SATA and USB ports (for internal and external storage)
• - At least one M.2 SSD slot on nearly all new models
• - Front audio and power connectors
  

ATX motherboards can be installed in most mid-size and large towers, but it's rare to find a small case that can accommodate a full-size ATX board. There are also larger cases designed to accommodate extended ATX motherboards.

Unless you have a specific purpose in mind, standard ATX cases are generally more efficient in terms of space utilization, leaving room for additional components rather than larger motherboards .

However, cases designed to house two PCs in one are an exception. If for some reason you need a PC that contains two complete systems, we offer the 1000D case, soon to be joined by the 9000D.

With a larger motherboard area, they tend to support a greater number of hard drives and add-on cards.

Although multiple graphics cards aren't really interesting now except in specific usage, an ATX card might be the right size for you if that's something you're interested in; it gives you all the space you need.

ATX motherboards offer a wider choice, between high-performance cooling systems and high-end components that can play an important role in system overclocking, as well as very affordable boards due to their easier to manufacture design.

As the most popular PC form factor, ATX motherboards also enjoy greater support from manufacturers. This gives you more choices in terms of aesthetics, features, and performance, making it easier to get a gaming PC that meets and exceeds your expectations.

When it comes to hardware options other than the motherboard for an ATX case, the biggest difference with the smaller M-ATX platform is the choice of case.

While CORSAIR cases are of course excellent no matter what form factor you're interested in, there are far more ATX options available, and these larger cases pave the way for far more powerful cooling solutions.

Nobody is perfect, and while an ATX PC has several advantages that make it an excellent choice for those building a new PC for work or entertainment, there is a major disadvantage to consider.

ATX chassis are bulkier. This means that they take up more space on your desk or floor and are generally heavier - although this depends on the choice of components and the material from which the case is made.

The MicroATX board is a compact version of the ATX board, reducing its length by about 25% to a size of 244 x 244 mm.

It supports the same processors and graphics cards as ATX motherboards, as well as four RAM slots, but typically lacks some additional features:

• Most MicroATX boards have a maximum of two PCI-E x16 slots, with the second slot mounted very close to the bottom of the board. This makes it difficult to install dual graphics cards in most cases designed for MicroATX cards.
• They also have fewer PCI-E x4 and x1 slots, fewer USB, SATA ports, and M.2 slots.
• It's only in terms of connectivity that M-ATX boards are slightly less versatile than their ATX counterparts.
  

MicroATX motherboards are also backward compatible, meaning that they will fit into any case that will accept an ATX motherboards. While this is an advantage when upgrading, it's not very useful when building a new PC. There's little point in building a MicroATX PC in an ATX case, as you lose many of the space-saving benefits of a MicroATX PC, as well as many of the benefits of a larger ATX feature set.

Modern MicroATX PCs have narrowed the gap considerably from their ATX counterparts, making a MicroATX PC a kind of complete tower that's smaller. You can choose the same powerful processors, graphics cards, and memory kits, but you can put it all in a more compact, lighter chassis.

The chassis are smaller and lighter, taking up less space on your desk or floor and making them more portable when you're going to LAN parties or moving your PC from room to room.

MicroATX cases are therefore ideal for those with limited space, but many also find the more compact appearance of a MicroATX PC more appealing. It's not as imposing as a full-size ATX case and can allow your PC to blend in more easily with your other electronic equipment or décor.

Despite this smaller physical footprint, modern MicroATX cases can still benefit from high-end cooling thanks to perfectly designed fans and heatsinks. Cable management is a little more difficult because there is less space to hide them, but with less open space, MicroATX cases can be much cleaner.

MicroATX PCs offer most of the advantages of modern ATX PCs, with some unique ones, but there are some things you just can't do in a smaller PC.

Massive, custom water-cooling loops are very difficult to achieve in a MicroATX PC. Clever loops are not impossible, but you won't be able to install multiple triple-fan radiators in MicroATX cases. Similarly, smaller MicroATX cases may have clearance problems with larger air coolers. As a result, the cooling potential of MicroATX PCs is lower. You can still run the most powerful CPUs and GPUs in a MicroATX PC, but you won't be able to cool them as well. If you have specific component and cooling plans for your new PC, make sure a MicroATX PC can accommodate them before committing to this format.

This lack of extra space also means you'll have fewer options for expansion cards and hard drives. With fewer PCI-Express and SATA ports, there are fewer options for connecting GPUs, hard drives, and M.2 SSDs, as well as less space to integrate them into the system.

Because the MicroATX platform is less popular than the ATX platform, there's also a bit less choice when it comes to cases and motherboards.

If you don't mind sacrificing some internal space and expansion options for a very compact build, and you like the idea of a small, unobtrusive PC, there's another platform worth considering: Mini-ITX. Mini-ITX is the next step down in size from MicroATX, and the next step up in terms of space savings.

Mini-ITX motherboards measure only 170 x 170 mm and represent the smallest common motherboard size.

• This very compact format is much more limited in terms of component possibilities, with only 2 memory slots, 1 PCIE 16x port, 1 M.2 slot, and very few USB & SATA ports.
• The price of these motherboards is generally equal or higher than an ATX motherboard who have more features, due to their small size, their design is more complex to produce
• They are also generally preferred when it comes to memory overclocking due to their shorter track length.

The choice of chassis is therefore critical, depending on what you want to integrate the cooling system must be optimized to support the most powerful configurations on the market.