Micro-ATX Vs Mini-ITX Vs ATX – What Size Motherboard To Choose?

As we know, motherboards come in a wide variety of shapes and sizes, although the most recognized are ATX, Micro-ATX, and Mini-ITX, three completely different motherboard formats that do not vary only. Whether you’re building a top-of-the-line gaming PC or a sleek and understated personal computer to navigate, the motherboard will always be an essential piece of hardware, and deciding which one to buy comes down to a few factors.

Next, we are going to show you how each motherboard differs, how this will affect your decision, and which one we would recommend specifically for each of your needs.

ATX vs Micro-ATX vs Mini-ITX

We are going to make a comparison between the major differences in terms of size, compatibility, and their pros and cons, to see what type of motherboard is the best option for your needs. So let’s dive deep into this Micro-ATX Vs Mini-ITX Vs ATX comparison.


The first item we’re going to address, and the most obvious difference when looking at these three types of motherboards, is size. Not all motherboards are built the same, and in general, they are all designed with different users in mind. But first, what is the form factor? The Form Factor simply refers to the specifications of the motherboard – its dimensions, the type of power supply, the location of the mounting holes, and the number of ports on the rear panel. The form factor determines the size of the cabinet, and the smaller form factors were developed to reduce the overall size of the product. In this way, we come to the question related to the dimensions of each motherboard.

  • Standard-ATX – 30.5 cm x 24.4 cm
  • Micro-ATX – 24.4 cm x 24.4 cm
  • Mini-ITX – 17 cm x 17 cm

As can be seen, both the physical dimensions and the size table present enormous differences between the three form factors for each type of motherboard. The most significant difference is between the Standard-ATX and the Mini-ITX: The mini has a square design and is almost half as long and 3/4 as wide as the standard. In the same way, the Micro-ATX is boxy in design, but it is longer and wider than the Mini-ITX. However, compared to the Standard-ATX, it is almost the same width, but it is 6 centimeters shorter. Now, what does all this mean, and how does it affect what each motherboard can support?

Motherboard Compatibility

After the differences in size – quite obvious – between the 3 types of motherboards, the most notable contrast is the capacity of the RAM memory that each of the form factors will support. Both the ATX and the Micro-ATX have slots for 4 RAM memories, compared to the Mini-ITX which only has 2. This means that the Mini-ITX can only support a maximum of 2 16GB RAM memories, that is a total of 32GB, while the other two formats can accommodate twice this. This is a pretty wide difference, especially if you’re trying to build a powerful platform, and you can slowly appreciate how this all fits together.

Besides the RAM capacity, another relevant contrast between the three models is the number of PCIe slots with which you can interact. A PCIe slot is a high-speed hardware interface where peripheral devices, such as the GPU (Graphics Processing Unit) and the sound card, are connected. To build a PC for gaming, and for configurations with the high-performance operation, PCIe slots are essential and therefore the ATX usually comes with about 7 PCIe slots. Notwithstanding this, specially designed mining motherboards can come equipped with up to 19 PCIe slots. Unlike the ATX, the Micro-ATX regularly comes with 4 PCIe slots, something that is still sufficient for most scenarios,

Finally, we come to the question of price, and you have probably already concluded that the prices of the 3 vary a lot from each other. And looking at the three forms and understanding their limitations, you probably think that the Mini-ITX is the cheapest version but, if so, let us tell you-you are wrong. Because of its smaller size, the mini-ITX is actually the second most expensive option, leaving the Micro-ATX as the most economical option available on the market. Clearly, the standard ATX is the most expensive for its compatibility, size, and its overall performance.

Pros & Cons

Each of the 3 form factors has its own pros and cons, and these will be determined by the type of computer you plan to build. Here are the general pros and cons for the everyday consumer.



  • A maximum of 19 PCIe slots
  • Increased RAM capacity
  • Supports multiple GPU configurations
  • Can be overclocked


  • More expensive
  • Your overall profile is bigger



  • It is the most economical
  • It’s the best overall product
  • Fits in most cabinets
  • Has better RAM capacity than Mini-ITX


  • It has a limited number of PCIe slots



  • It is the smallest


  • Supports a maximum RAM memory of 32gb
  • It has only 1 PCIe Slot
  • It is more expensive

As seen in the table above, each format has its own pros and cons related to different issues. For example, you can start from the fact that the Mini-ITX can only be used for the smallest PCs and therefore it would not be the first option for someone who wants to build something much more powerful and versatile. Clearly, the Micro-ATX is the best option overall, as it is smaller than the ATX while still offering decent RAM capacity and a good number of PCIe slots. This leaves the ATX for those consumers who want to build a powerful beast that is capable of handling literally all types of scenarios, including multi-tasking and data mining.

ATX Vs Micro ATX Vs Mini ITX. Which one should you choose?

You’re in the part of the article where you’ve probably already got a pretty good grasp on what each form factor has to offer, and you’re trying to decide on one. If that were the case, below we are going to discuss some likely scenarios in which each type of factor can be used:

Building a high-performance gaming PC.

If you are looking to buy and gather the necessary elements to build your own gaming PC, you will have to ask yourself two questions before choosing the motherboard form factor that best suits your needs. First of all, how powerful do you need your platform to be? Most games these days can be run using a decent CPU and a good quality singular GPU. That said, for a price point and also for a practical question, we would expressly recommend a Micro-ATX motherboard, because it has a decent capacity for RAM and because it allows up to 4 PCIe slots running simultaneously. The only scenario in which the Micro-ATX would not fit, would be the case in which you need to have a greater capacity of PCIe outputs, for example, when it comes to the need to have a configuration with multiple GPUs for mining. But also, if you want to do some extreme overclocking, or if you just want to add something to the overall aesthetics of the build, then you should probably go for the ATX.

Building a Computer for Professional Work

Most of the advice and recommendations that are given to build a computer to work are quite similar to those that would be given for a gaming setup. Basically, unless you do bulk photo and video editing with many windows running simultaneously, you shouldn’t need anything bigger than the Micro-ATX motherboard format. In this format, you have enough Ocie slots, and the same RAM memory capacity as the ATX, so basically you will have a platform that will deliver more than enough power to face your load of tasks.

Building a home desktop PC

If you are considering building a desktop PC for your home, then your options are a bit more varied, depending mainly on design and performance. For example, if you want to build something discreet and elegant, then the Mini-ITX is hands down the best way to go. It is more expensive, but the size really makes a difference. The other option, if the size is not your primary concern, would be the Micro-ATX again, because it is more suitable as it is a more complete product.


We’ve compared the sizes of ATX vs Micro ATX vs Mini ITX motherboards to really identify their differences and to help you choose your next motherboard.

Whether you are building a monster gaming rig or a small desktop PC that doesn’t take up tons of space, you now know that there is a perfect motherboard on the market waiting to accommodate your needs.