Motherboard Sizes - Decoding The Different Types of Motherboards

Motherboard Sizes - Decoding The Different Types of Motherboards

Motherboard Sizes - Decoding The Different Types of Motherboards

Motherboards are the backbone of every computer, playing a critical role in system performance and capabilities. As the central hub where all other components connect, the motherboard's features and specifications directly influence the efficiency and potential of your PC. Whether you're assembling a new build or considering an upgrade, understanding the various types of computer motherboard sizes – from ATX to Mini-ITX – is essential. In this guide, we'll explore the different motherboard sizes and formats available so you can make an informed decision for your next project.

Exploring Different Types of Motherboards

The size of a motherboard corresponds to its type — so we’re here to talk you through some of the most common numbers that pop up.

PC Motherboard Sizes At a Glance

Motherboard Type

Standard Size


305mm x 244mm


244mm x 244mm


170mm x 170mm

Note: The size for E-ATX motherboards can vary, as there is no strict industry standard for this form factor. The size given above is a common dimension, but it's always best to check the specifics for a particular E-ATX motherboard model.

ATX Motherboards:

  • Design and Size: ATX motherboards measure 305mm x 244mm, providing a spacious platform for building high-performance systems. This size allows for better layout, airflow and cooling solutions.
  • Expansion Capabilities: They typically come with 4-7 PCIe slots — this means plenty of room for multiple GPUs, sound cards, network cards and other PCIe devices. ATX PC motherboards are ideal for users who need extensive expandability for gaming, video editing or server applications.
  • Memory and Storage Options: Most ATX motherboards support four or more RAM slots, enabling dual or quad-channel memory configurations. They also offer numerous SATA and M.2 slots for ample storage options.
  • Connectivity and Features: These motherboards often include a wide range of connectivity options like USB 3.x, Thunderbolt and high-speed Ethernet. Advanced features like built-in Wi-Fi, RGB lighting and comprehensive fan controls are also common — ideal for gamers who want to customise their rig.

Micro-ATX Motherboards:

  • Compact Size: Measuring 244mm x 244mm, Micro-ATX motherboards are smaller than ATX but larger than Mini-ITX. This size strikes a balance between space-saving and functionality.
  • Expansion Slots: They typically have 2-4 PCIe slots, sufficient for a single GPU setup and a couple of additional cards. This makes them suitable for most gaming and general computing needs.
  • Memory Support: Micro-ATX boards usually support up to four RAM slots, similar to ATX, allowing for decent memory capacity and performance.
  • Affordability: These motherboards are often more affordable than ATX models, making them a popular choice for budget-conscious builders who still want room for system growth.

Mini-ITX Motherboards:

  • Ultra-Compact Design: With dimensions of 170mm x 170mm, Mini-ITX motherboards are designed for small form factor cases. They are ideal for compact, space-efficient builds.
  • Limited Expansion: Typically, they have only one PCIe slot, which is usually occupied by a graphics card. This limits expansion but is sufficient for many gaming and media centre setups.
  • Memory and Storage: Most Mini-ITX motherboards have two RAM slots and a limited number of SATA and M.2 slots due to their size constraints.
  • Specialised Use: They are perfect for building HTPCs, portable gaming rigs, or any system where space is at a premium. Despite their size, many Mini-ITX motherboards come packed with features like Wi-Fi, high-quality audio, and adequate cooling solutions.

All motherboard sizes offer unique advantages, catering to different user needs and builds. From the expansive ATX to the compact Mini-ITX, the choice depends on your specific requirements for performance, expansion and form factor.

FAQs About Computer Motherboard Sizes

How can you tell what size motherboard you have?

To determine the size of your motherboard, you can measure its dimensions. Measure the length and width of your motherboard and compare these measurements to standard motherboard sizes (ATX, Micro-ATX, Mini-ITX, etc.). Alternatively, you can look up the model number of your motherboard online, which should provide you with its exact form factor and dimensions.

What size motherboard should I get?

Your ideal motherboard size depends on your specific needs and the size of your computer case. If you have a large case and need multiple expansion slots for GPUs, RAM and other components, an ATX motherboard is a good choice. For smaller builds, like home theatre PCs or compact gaming systems, a Micro-ATX or Mini-ITX motherboard could fit the bill. Consider what components you plan to use and how much space you have when tossing up between computer motherboard sizes.

Are all motherboards the same size?

Nope — PC motherboard sizes vary. There are several different form factors, each with its own standard size. Common types include the previously discussed ATX, Micro-ATX and Mini-ITX, as well as others like E-ATX and Nano-ITX, which have different dimensions. The size you choose depends on your case size and your computing needs.

Are all ATX motherboards the same size?

No, not all ATX motherboards are exactly the same size. The standard dimensions for an ATX motherboard are 305mm x 244mm. However, there can be slight variations in size within the ATX specification, especially with some models offering additional features or unique designs. It's always a good idea to check the specific dimensions of the motherboard model you're interested in.

Does the size of a motherboard matter?

The size of your motherboard definitely matters — it affects the compatibility with your computer case, the number of expansion slots available and the overall layout of your system. Larger motherboards (like ATX) offer more expansion slots and features but require bigger cases. Smaller motherboards (like Mini-ITX) are great for compact builds but offer fewer expansion options. Your choice should align with your build's intended use, space availability and desired features.

The Mother Lode of Motherboards

Ready to find the motherboard that will form the foundation of your dream PC? Look no further than Mwave. As Australia’s best online tech retailer, our extensive range of motherboards is bound to have something that ticks all your boxes. Whether you're after the expansive possibilities of an ATX board, the balanced approach of a Micro-ATX or the compact efficiency of a Mini-ITX, we’ve got you covered. Dive into our collection and choose the motherboard that meets your needs and ambitions!

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