Motherboard — The Main System Board
The backbone that connects every component into one working computer. Explore it in the interactive 3D viewer below, with the key facts about how it works and how it fits into a PC build.
By PC Anatomy contributors · Published 2026-08-11 · Updated 2026-11-12
What Is a Motherboard?
A motherboard (also called the mainboard or system board) is the main printed circuit board of a computer that physically and electrically connects every component — CPU, RAM, GPU, storage, and peripherals.
The motherboard is the main printed circuit board that physically and electrically connects every component. Power, data, and signals all travel through its traces, slots, and headers, making it the nervous system of the PC.
What Does a Motherboard Do?
The motherboard distributes power from the power supply, routes data between the CPU, RAM, GPU, and storage, and hosts expansion slots, ports, and headers — acting as the nervous system of the PC.
- Distribute power from the PSU to every component.
- Route data between CPU, RAM, GPU, and storage.
- Host expansion slots, ports, and headers.
- Report system status and manage power states via the BIOS.
How Does a Motherboard Work?
Copper traces on the board's layers carry data and power between the CPU socket, memory slots, PCIe slots, and chipset. The chipset manages connectivity — USB, SATA, networking, and audio — and reports system status to the BIOS/UEFI, which initializes hardware at startup.
Example Specifications
These values illustrate a common desktop setup. Specifications vary by model; check the manufacturer’s documentation before choosing or installing hardware.
| Form Factor | ATX / mATX / ITX |
|---|---|
| CPU Socket | LGA 1700 / AM5 |
| Chipset | Z790 / B650 |
| RAM Slots | 4 × DDR5 |
| Expansion Slots | PCIe 5.0 ×16 |
CPU Socket
The socket matches the CPU family (for example LGA 1700 for Intel or AM5 for AMD) and is the single most important compatibility point between the motherboard and processor.
RAM Slots
Motherboards typically have two or four DIMM slots supporting one RAM generation, such as DDR4 or DDR5. Slot placement determines dual-channel operation — installing matched modules in the correct slots doubles memory bandwidth.
PCIe Slots
PCIe (PCI Express) slots connect expansion cards. The top x16 slot is usually wired directly to the CPU for the GPU, while additional x16, x4, and x1 slots handle capture cards, networking, and other add-in boards.
Storage Connections
Modern boards offer M.2 slots for NVMe SSDs (wired over PCIe) and SATA ports for 2.5-inch SSDs and hard drives. Some boards share bandwidth between M.2 slots and certain SATA ports, which is documented in the manual.
Power Connections
The 24-pin ATX connector powers the board, while the 8-pin CPU power connectors feed the processor. VRMs (voltage regulator modules) around the socket convert this power into stable, clean voltages for the CPU.
Motherboard Form Factors
Common sizes are ATX (305 × 244 mm), micro-ATX, and mini-ITX. Smaller boards fit smaller cases but offer fewer PCIe slots, RAM slots, and M.2 sockets.
Motherboard in a PC Build
The motherboard determines which CPU, RAM generation, and storage your build can use, and its form factor must match the case. Matching the chipset to the CPU's features (overclocking, PCIe lanes, port count) is what makes a build fit together cleanly.
Choosing a motherboard determines which CPU, RAM, and storage you can install — its socket and chipset define your upgrade path. Builders match boards to cases so ports and standoffs line up.
Related Computer Components
Every part of a computer works together. Learn how the Motherboard connects with the rest of the system:
References and further reading
Frequently Asked Questions
What does a motherboard do?
A motherboard connects every computer component: it hosts the CPU, RAM, GPU, and storage, distributes power from the PSU, and routes data between all parts so they work as one computer.
What is a motherboard chipset?
The chipset is the motherboard's connectivity controller. It manages USB ports, SATA storage, networking, and audio, and decides which CPU features (like overclocking or PCIe lane allocation) a board can offer.
How do I know which motherboard to buy?
Choose a motherboard whose socket and chipset match your CPU, whose RAM slots match your memory generation, and whose form factor fits your case. Then check that it has enough M.2 slots, SATA ports, and USB ports for your hardware.
What is the difference between ATX and micro-ATX?
ATX is the standard full-size motherboard format with more PCIe slots, RAM slots, and ports. Micro-ATX (mATX) is a shorter version that fits in smaller cases while keeping most core features.
Explore the Motherboard in 3D
Use the interactive viewer to rotate, zoom, and inspect the Motherboard. Drag to orbit, scroll to zoom, and use the toolbar to reset the camera.
