If you\u2019re interested in building your first PC, either for gaming or productivity, then you\u2019re probably noticing that PC components come in different sizes and shapes, which can be confusing for new-comers. In truth, once you do a little bit of digging, you\u2019ll notice that most components are compatible with each other and that putting together a PC is much, much simpler than one might think. Some people even go as far as comparing it to playing with a LEGO set. On that note, let\u2019s take a look at the different motherboard sizes, the pros and cons of each, and what size would best suit your particular needs. With that in mind, you\u2019re likely already familiar with the term ATX, which comes up a lot when people are talking about motherboards. But what does ATX mean? ATX is an Intel-coined term and stands for Advanced Technology eXtended. It refers to an industry standard when it comes to motherboard and power supply compatibility and has later incorporated PC cases. By getting everyone to use a standard form factor when manufacturing a component, the PC market became more diverse and accessible to a larger audience.\u00a0 Today, we have a big number of industry-standard motherboard sizes, each of them having similar features, advantages, and drawbacks. Let\u2019s start by taking a look at everyone\u2019s favorite, the ATX form factor. ATX A full-size ATX board has a height of 305mm and a width of 244mm, or 12 x 9.6 inches. When you\u2019re planning a build, if you\u2019re picking up an ATX motherboard, you\u2019re going to want to pair it with a ATX-compatible PC case. These can either be super-towers, full-towers, middle-towers, or mini-towers. As long as they\u2019re built to support the ATX format, then the board will fit 10\/10 times. The ATX board is built for running all sorts of systems. With at least 4 RAM DIMMs, it can support dual or quad-channel memory, giving the user better performance in specific applications over a board that doesn\u2019t support this type of configuration. ATX boards typically have 7 expansion slots, allowing you to run up to 4 GPUs with Nvidia SLI or AMD Crossfire if your case and power supply are fit to power and house such a system. Moreover, the big number of expansion slots allows users to install quality of life upgrades, like a better network card that can even support Wifi, Bluetooth adapters, sound cards, USB hubs, and more.\u00a0 This type of motherboard usually provides manufacturers with enough space to install big heatsinks, an intricate VRM (voltage regulator module, we\u2019ll explain later), a bigger rear IO, more SATA and USB header connectors, giving you a better experience. This type of motherboard is powered by a 24-pin connector with an 6\/8 pin connector for the CPU, allowing you to run high-end processors, and even overclocking the processors on unlocked motherboards.\u00a0 Pros \tHave a complete IO \tPlenty of room for heatsinks \tGood VRM compared to the smaller boards Cons \tCan\u2019t fit into compact form-factor cases \tMore expensive than mATX and mini-ITX motherboards Extended ATX (EATX) Extended ATX boards are slightly bigger ATX boards. I know, kind of anticlimactic. These boards are slightly bigger, measuring 305x330mm (12 x 13 inches rather than 12 x 9.6), giving you more connectors. They sometimes have dual-socket support, allowing you to run two CPUs using the same board, but that\u2019s not always the case. Pros \tSome support dual sockets \tSome have more RAM DIMMs \tMore connectors Cons \tFewer products on the market \tCan\u2019t fit in some PC cases \tMore expensive without adding any real value XL-ATX Unlike the other featured motherboard sizes, XL-ATX boards do not abide by a standard height and width. XL-ATX boards are very rare, with only a handful of manufacturers releasing this quirky format in the past decade. As with the Extended ATX products, they have no clear advantage over their smaller ATX cousins, other than more memory DIMMs (up to 8) for building powerful workstations. With that said, XL-ATX motherboards are slowly disappearing from the market, so it\u2019s pretty unlikely that you\u2019re going to run into this format anytime soon. Pros \tSupports more memory Cons \tVery rare \tCan\u2019t fit in most cases \tExpensive because of their obsolescence and small quantity Micro ATX (mATX) mATX boards have a square shape, measuring 244x244mm (9.6x9.6 inches). They typically have between 2-4 RAM DIMMs, which is great if you\u2019re looking to have a powerful PC in a compact case, and have up to 4 expansion slots, allowing you to run dual-GPU systems in a handful of cases. IO-wise, you\u2019re going to have enough to get by. Manufacturers also often include extra features like built-in Wifi with this type of card, so you won\u2019t have to use one of your few expansion slots to have such a feature available. In terms of build quality, you can find boards that are on par with high-end ATX boards around the same price. While you lose some inputs and outputs, you gain a smaller form-factor and you\u2019ll have access to a whole new lineup of PC cases to build in. When building in a small form-factor case, it\u2019s important to dedicate enough time to cable management for better airflow, and investing in the right components for a cohesive, well-thought rig. Pros \tSmaller than ATX while retaining most of the features \tAbility to include in more compact cases Cons \tInferior power-delivery, not suitable for high overclocks Mini-ITX Mini-ITX boards are 170x170mm (6.7x6.7inches) and are the smallest type of board that can still run full-sized PC components. While the mATX could still function in most aspects like an ATX board, mini-ITX boards are more of a compromise. You\u2019ll find no more than 2 RAM DIMMs on the typical mini-ITX, with a single expansion slot. With no support for multi-GPU configurations and not enough power to run high-end processors, since most of them are powered using a 4-pin connector, limiting the type of hardware that you can run efficiently on such a motherboard. That being said, CPUs are more power-efficient than ever, so you can still find plenty of boards that will allow you to overclock, you\u2019re just not going to reach very high values with the limited VRM and cooling options. Pros \tForm factor allows you to build in a variety of cases \tVery compact \tCan still run a fully-fledged PC Cons \tLimited IO \tPower delivery is not ideal for high-end components What\u2019s VRM and Why It\u2019s A Critical Element for a Well-Built Motherboard VRM stands for the voltage regulator module. It\u2019s comprised out of MOSFETs, chokes, and capacitors. Each of them impacts the way power is distributed from the motherboard to the other components.\u00a0 MOSFET stands for metal oxide semiconductor field-effect transistor. Pretty boring, but it\u2019s essential in ensuring that your processor runs efficiently at a stable current. Much like the power supply converts alternating current to direct current, the MOSFETs also amplify or switch the electronic signal to match a particular component\u2019s need. The chokes are inductors that are used to limit the passing DC to a certain frequency, further ensuring a stable voltage while powering your CPU. Transistors function in a similar way. Whether you\u2019re planning on buying a premium, gaming motherboard or are looking to snatch a good price on a clean-looking, business branded model, you should always purchase a product that has an intricate VRM. The more chokes, MOSFETs and transistors, the better the performance and reliability.\u00a0 Lastly, make sure that your future motherboard has solid-state transistors. Fluid-based transistors can burst, throwing acid onto your components, damaging the circuits and cutting off power to multiple sectors of the board.\u00a0 What Type of Board Do You Need All in all, it all boils down to personal preference. If you\u2019re working with limited space in your home or at the office, then a small form-factor PC is a great choice. A mini-ITX board can rock a potent CPU-GPU combo, allowing you to run demanding software with a compact build. While it\u2019s easy to source components for a compact system, the building process is kind of a drag, and inexperienced PC builders will struggle to get good cable management, resulting in bad airflow and high temperatures during bigger workloads. Fan size is also limited, so this type of system will be louder. If you\u2019re not constricted by space, then I think that an ATX-based PC is the way to go. Most of the time you\u2019ll get a better VRM, better cooling, and you\u2019ll always get more features. You can use the expansion slots to further customize your build, and you can run powerful hardware at great temperatures. Cooling will never be an issue, with middle-tower and full-tower cases supporting air, hybrid, and water-cooled builds, and the entire building process is much more user-friendly.