What is a Motherboard?

Thinking about building a new PC or upgrading your current setup? Then building your own system gives you full control over what matters most to you: performance, aesthetics, budget, or all of the above.

One of the most important components you’ll need to consider is the motherboard. It’s the central hub that connects your processor, memory, graphics card, and more. Choosing the right motherboard ensures compatibility with your CPU and other components, so it’s worth taking the time to get it right.

The motherboard is the backbone of your computer. It allows all the different parts of your system, such as the CPU, RAM, GPU, storage, and peripherals to communicate with each other. It also determines what features your PC supports, from connectivity options like USB and Wi-Fi to expansion slots and storage configurations. In short, your motherboard defines the capabilities and limitations of your entire build.

Motherboards are printed circuit boards packed with connectors, slots, and integrated features. Here are some of the key components:

• CPU Socket – Where your processor is installed.
• RAM Slots – For your system memory (DDR4, DDR5, etc.).
• PCIe Slots – Used for graphics cards, sound cards, and other expansion cards.
• Chipset – Controls communication between the CPU and other components.
• Storage Connectors – SATA ports and M.2 slots for SSDs and hard drives.
• Power Connectors – Deliver power to the CPU and motherboard.
• Rear I/O Ports – USB, Ethernet, audio, and display outputs.
• Onboard Features – Integrated audio, networking, Wi-Fi, ARGB headers

These components work together to form the foundation of your system and influence everything from performance to connectivity.

Motherboards come in several sizes, known as form factors. These sizes follow the ATX (Advanced Technology eXtended) specification, which ensures compatibility between motherboards, cases, and power supplies. That means an ATX motherboard will fit in an ATX case and work with an ATX PSU—making your build process smoother and more predictable. Yay for standards!

The most common motherboard size is ATX (full-size), measuring 305mm x 244mm (12in x 9.6in). It offers ample space for key components, typically supporting:

• Up to 4 DIMM slots for memory
• Multiple PCIe slots for expansion cards
• Up to four M.2 slots for high-speed SSDs

ATX boards are ideal for most PC builders, offering room for premium features such as high-quality onboard audio, Wi-Fi 7, ARGB headers, internal USB ports, and fan connectors.

If you're planning to overclock your CPU or take advantage of modern auto-overclocking features, ATX is a great choice. These boards have the space for robust VRMs and heatsinks, ensuring stable power delivery and thermal performance.

Micro ATX motherboards are a compact, generally budget-friendly options, measuring 244mm x 244mm (9.6in x 9.6in). While smaller, they still offer plenty of core features:

• Up to 4 RAM slots
• PCIe and M.2 slots, although fewer than you’ll find on ATX
• USB4, Wi-Fi 7, and integrated audio

Power delivery may not be as strong as on ATX boards, but many mATX models still perform well. These boards are popular with gamers who want to prioritize their GPU spend while keeping the rest of the build affordable.

Mini ITX is the smallest mainstream form factor at just 170mm x 170mm (6.7in x 6.7in). While many full-size cases support Mini ITX, they’re best paired with compact cases like the CORSAIR 2000D.

Due to their size, Mini ITX boards make some trade-offs:

• Typically only have 1 PCIe x16 slot
• 1–2 M.2 slots (often one on the rear)
• Fewer USB and SATA ports

Mini ITX boards are a niche choice and often more expensive than mATX, but they’re perfect for small-form-factor builds that still offer impressive performance.

Extended ATX boards are the largest standard size, designed for high-end systems and workstation builds. They measure 305mm deep, with widths ranging from 257mm (10.1in) to 330mm (13in).

E-ATX boards can offer:

• Support for dual CPUs
• Up to 8 RAM slots
• Enhanced VRMs and cooling
• Extra PCIe and storage options

They’re typically more expensive and not necessary for most users, but if you’re planning an extreme build, they’re worth considering. Just make sure your case supports E-ATX, although many modern cases like the FRAME 4000D do.