There are many types of motherboards out there with striking differences, largely depending on the manufacturer. However, there’s one aspect of motherboards that are pretty much universal: the form factor. Here’s just an example of different form factors: AT, ATX, Micro-ATX, and ITX. If you’ve ever built a computer before, you may have seen these letters in the past, but might not have been sure exactly what they mean.

That’s the goal for this overview: To inform you of what all these different types of motherboards are, why they matter in the scheme of building your own computer, and what they do differently than the others. It’s very important information to know when building a PC, and having the technical knowledge is also a big bonus!


ATX Motherboards

ATX Motherboard

The Advanced Technology Extended (ATX) motherboard, developed by Intel in the 1990’s, replaced the AT-style motherboard that ruled the PC world for many years. One of the major aspects of this new style is that the processor and memory slots are placed in such a way that the system can run cooler. It’s also engineered so that the processor and memory slots are to the right of the expansion slots, allowing users to throw in full-length expansion cards (e.g. cards that will span the length of the inside of the computer case).

Most ATX motherboards measure in at 305 x 244mm, which is important to keep in mind when choosing a case.



One of the great things about Micro-ATX motherboards, is that they can fit in the same cases that full size ATX motherboards can. This is because Micro-ATX motherboard share the width and mounting hole patterns of the traditional ATX boards. Another benefit is that Micro-ATX machines tend to be built with smaller power supplies, reducing power consumption, and thus heat, helping to keep the hardware components cooler. Unfortunately, temperatures could actually go up if the motherboard is placed in a small case with poor ventilation, but that’s the case with any motherboard.

As you might expect, the Micro-ATX motherboard is an ATX, just with a smaller form factor. This does come with some pitfalls. While you may have a smaller footprint, it also means that you lose memory slots, expansion slots, motherboard headers, and even integrated components, which could prove to be troublesome, depending on the type of system you’re building.

The Micro-ATX motherboard takes on more of a square form, measuring in at a standard 244 x 244mm. Micro-ATX motherboards aren’t all bad. Their smaller form factor can make things difficult as you’ll likely need to make some tradeoffs, but at the same time can also benefit you. It all depends on what you’re planning to use it for.



While it’s good to know the differences between ATX and Micro-ATX motherboards, I personally find ITX solutions to be the most interesting of the two. The ITX motherboards were originally developed by VIA, intended for specialty use, such as embedded systems like smartphones and tablets. In other words, the ITX motherboards aren’t just one form factor, but a family of different sizes, all for different types of electronics. Here’s the list of ITX form factors you can find out in the world:

  • Mobile-ITX: 60 x 60mm
  • Nano-ITX: 120 x 120mm
  • Pico-ITX: 100 x 72mm
  • Mini-ITX: 170 x 170mm

As you can see, even the largest ITX motherboard is significantly smaller than even the Micro ATX motherboard mentioned earlier. You can find these types of motherboards in the aforementioned smartphones and tablets, along with set-top boxes like the Android or Apple TV, and so on. Interestingly, you can even find the Mini-ITX motherboard in some PC’s, as the mounting holes line up with three or four of the holes found on ATX-style boards.

Which Of These Motherboards Is Ideal For Your PC Build?

With so many different options for motherboards, it can be difficult to decide which one is perfect for your intended PC build. If you’re constructing a gaming rig and plan on using it for media and content creation as well, a full-size Standard-ATX motherboard is your best option. This is because you’re going to need all of the extra PCI Express slots and DIMM slots you can get your hands on to achieve the performance you’re aiming for.

For those not focused on performance and content creation, the Micro-ATX motherboard could be the right solution. You get just enough PCI Express and DIMM slots that gaming is still possible, along with the ability to do some light content creation.

Finally, you can use the Mini-ITX motherboard in smaller systems such as a home theater PC or other very specialized applications, particularly where space might be at a premium. Aside from that and other similar uses, the Mini-ITX solution just isn’t good for any sort of gaming or content creation.


One thing these motherboards all have in common: they’re one the most important piece of technology in any computer-based system because they connects all of the other components together. This article has really only scratched the surface on what there is to know about them. You can find much more detailed and technical information on them from Cengage Learning, who offers a free resource that gets into the nitty gritty aspects of motherboards–it’s a really great read!

If you’ve got any questions about motherboards, be sure to leave a comment below or start a new discussion in our community forum.