ATX vs Micro ATX vs Mini ITX Motherboard Compared. How to pick

From the CPU and graphics card to the RAM and CMOS battery, virtually all PC components are connected to the motherboard either directly or indirectly. This allows for proper communication between the different components within the system for the best performance.

However, motherboards are available in different sizes and layouts, also known as form factor. A motherboard’s form factor specifies its dimensions, supported power supply, number of slots, layout of the mounting slots, and even the overall shape.

The three most common motherboard form factors include ATX, Micro ATX, and Mini ITX. So, how do these form factors compare beyond their differences in size? In this article, you’re going to understand how these form factors compare in terms of differences and similarities in their features and overall working.

Comparison Table for ATX vs Micro ATX vs Mini ITX

Form Factor





12 x 9.6 inches

up to 7 PCIe slots;

Up to 8 RAM slots;

Suitable for multi-GPU setups

Micro ATX

9.6 x 9.6 inches

Up to 4 PCIe slots; 4 RAM Slots;

Most popular and best budget option;

Great size for most cases;

Ideal for single-GPU setups

Mini ITX

6.7 x 6.7 inches

1 PCIe Slot; 2 RAM Slots;

Ideal for compact PC builds;

Perfect option for simple gaming setups

Differences: ATX vs Micro ATX vs Mini ITX

  • Size

From the first impression, the most noticeable difference between these three form types is their sizes.  As detailed on our comparison table, the ATX form factor is the largest among the three. Then, the Micro ATX comes second in terms of size, measuring at 9.6 x 9.6 inches and the Mini ITX is the smallest of all the form factors.

When it comes to choosing a form factor based on the size, you should pick one that perfectly fits into your PC’s case. Mid to large sized cases can accommodate each of these form factors without any issue.

The best thing is that the latest cases come designed with a standardized layout that allows you to fit even the smallest motherboard into extra-large cases.

  • RAM Capacity

Another key difference among the three motherboard form factors is the number of RAM slots included. That said, ATX motherboard come equipped with up to eight RAM slots, the Micro ATX models are designed with four memory card slots whereas the Mini ITX can only accommodate two RAM modules.

As such, installing a 2×16 GB memory kit on a Mini ITX motherboard means that it can support up to 32 GB RAM while the Micro ATX can accommodate almost 64 GB. On the other hand, the ATX motherboards can support higher amounts of up to 128 GB.

Though increased RAM amounts yields better performance, a memory of about 16GB or 32 GB is more than enough to smoothly run a vast majority of programs and games. This means that with a Mini ITX motherboard, you can comfortably enjoy all your games without any problem.

  • PCIe Slots

The next noticeable difference is the number of PCIe slots incorporated in these form factors. The ATX models leads with up to seven PCIe slots compared to Micro ATX’s four and a single one on the Mini ITX models.

This means that the ATX models allows you to add extra graphics cards, video cards and other expansion cards in the future compared to the rest of the form factors.

  • Price

While the Mini ITX models are the smallest among the three form factors, they are also the most expensive among the bunch. This is mainly because of their complex circuitry, able to bring everything on the compact size.

In contrast, the Micro ATX and ATX motherboards start at a much lesser price compared to the Mini ITX models.

All in all, the Micro ATX form factors make the best budget options since you can easily find a quality pick at a much reduced price.

Similarities: ATX vs Micro ATX vs Mini ITX

While these motherboard form factors are different in size and features included, they also share a good number of similarities:

  • Support the same CPU

If the three motherboard form factors share a common generation, then this means they can support the same processor technologies. This is important as you can enjoy better performance and processing speeds even with a Mini-ITX motherboard.

  • Can support same graphics cards

As long as your graphics card can fit into the PC’s case and into the slots of the PCIe x 16, means you can mix and match the cards without an issue. This also means you can install a PCIe 4.0 graphics card into a motherboard with a PCIe 3.0 configuration.

  • Possess similar back panel ports 

No matter the size of the motherboard, the back panel connectors and ports take up almost the same amount of space on all the three form factors.

However, the type and number of ports a motherboard features is mainly determined by the price- high-end models will often come with more and modern port types compared to cheaper options.

Conclusion: ATX vs Micro ATX vs Mini ITX

As you’ve seen from our article, motherboards come in different form factors, which are different in terms of their sizes and features. Besides their differences in size, these form factors also share several things in common.

When it comes to choosing the best one among the three, you should consider how you intend to use the system, the type of system you intend to build and the number of RAM and PCIe slots you need.

For gaming purposes, you may consider choosing the Micro ATX or the ATX model as they offer increased configuration options and some extra PCIe slots.

If you want the best value for your money, then you may choose the ATX motherboards and the Mini ITX model if you’re planning on building a compact system.