Motherboard Form Factors – CompTIA A+ 220-1101 – 3.4

The form factor of a computer can have a significant impact to configuration options and future upgradability. In this video, you’ll learn about motherboard form factors and the differences between the ATX and ITX motherboard families.


The fundamental physical component within all of our computers is the motherboard. The motherboard generally contains the CPU, spaces for memory. There’s connectivity to power. You’ve got additional slots that you can use to expand the capabilities of the system. And everything involving the entire process of using your computer begins and ends with the motherboard.

As you can imagine, there are different motherboards that have different sizes depending on your requirements. And in this video, we’ll look at some of the most popular sizes that are in use today. There’s usually a basic layout on these motherboards regardless of the size because most motherboards will include a CPU or slots for memory or expansion. But the amount of expansion slots and the amount of additional memory slots may vary depending on the size of the motherboard.

One thing that doesn’t seem to change much between motherboard versions, though, is the power connector. All of these power connectors are very standardized. And to keep compatibility through all of these different systems, you’ll find that most motherboards will use the same type of power connection. We generally choose a motherboard based on the size of the case we might own or how much future expansion we might need. And in some cases, we might choose a motherboard based on how much airflow is required to keep that system cool.

If you look at Wikipedia, there are over 40 different sizes and types of motherboards. Thankfully, there are only two or three that are very popular, and generally, you’ll find motherboards that are relatively compatible between the different cases. The big difference will be how many features and how much room do you need for this motherboard.

Here’s an example of where you might need to make decisions over the size of motherboard. On the left side is a full sized desktop computer. On the right side is a small form factor device. You can see that the desktop computer has a lot of room for motherboards, and you can fit a very large size especially when you compare it to the smaller devices that can only fit the smallest of motherboards.

The CompTIA exam objectives tend to focus on which motherboard you might choose for a particular task and how you might install that particular motherboard. You wouldn’t generally have to memorize exact dimensions of a particular motherboard models, and generally, you’re choosing between two or three different motherboard types to answer one of these questions. For example, which motherboard would you use if you’re putting together a media center? Maybe you have a video editing system, or maybe you’re using a thin client. There’s different motherboards and different sizes for each of these scenarios. So it’s useful to understand when you would use a particular motherboard for a particular task.

The CompTIA exam objectives focus on two different motherboard families. One is the ATX family, and the other is the ITX family. The standard ATX is the motherboard that you’d most likely find in a desktop computer. It has a lot of real estate, plenty of expansion slots, lots of memory, and there’s plenty of room inside of a desktop for this size of motherboard. The smaller systems, though, may require a much smaller motherboard, and you can see this Mini-ITX motherboard is very different in size than the larger standard ATX. You might use ATX on a desktop system, but a Mini-ITX motherboard might be perfect for the small form factor computer that you keep next to your television.

These larger desktop motherboards are advanced technology extended motherboards or ATX. It’s a standard that’s been around since 1995, and it’s one that’s become very popular for desktop computers. If you’re buying a computer for a desktop today, you’re probably buying an ATX motherboard. There have been a number of updates to the ATX standard over the years. So the ATX motherboard you find today will probably have a power connector that’s 20 or 24 pins in size, and there may be additional power on the motherboard for CPU.

Here’s a better view of this particular motherboard. This is an ASUS Maximus VII Hero ATX motherboard, and you can see the connection for the power. We have a number of different expansion slots. There are four slots available for memory, and you can see the additional power right next to the CPU for CPUs that require some additional voltage.

If you need more of a smaller form factor for your motherboard, you might want to look at an ITX motherboard. This is a style of motherboard that was created by VIA Technologies in 2001, and it’s perfect for small form factors and smaller cases. Although this is relatively small compared to ATX, the screw holes in this motherboard are exactly the same as an ATX motherboard. So you could even install this very small motherboard into a much larger case that was originally designed for ATX.

But the real value of these smaller motherboards is that you can fit them into much smaller cases which can then fit into much smaller areas. I mentioned earlier having a computer right next to your television, and in those cases, it would be nice to have something in a much smaller case instead of having a full size desktop system right next to your media center.