The Complete Handbook of Motherboards

Chapter 1: Understanding Motherboards

A motherboard is a printed circuit board that serves a single, critical function: it is the central electrical and logical interconnect that allows the processor, memory, storage, and peripheral devices in a computer to communicate with one another. It is not the "brain" of the computer—the processor is. It is not the "power supply" of the computer—the power supply unit is. The motherboard is the nervous system: every signal, every data transfer, every piece of communication between components flows through the motherboard's electrical pathways and is coordinated by the logic circuits etched into its surface.

In a desktop or laptop computer, the motherboard physically occupies a relatively small footprint—typically between 170 and 305 millimeters on its longest edge—but it performs an extraordinarily complex set of functions. You can hold one in your hand. Yet its failure will render an otherwise intact computer completely unusable.

What a Motherboard Actually Does

To understand why a motherboard matters, consider a real-world scenario. You have just purchased a new processor—a high-end Intel Core i9 or AMD Ryzen 9. You have purchased 64 gigabytes of RAM. You have purchased a graphics card. You have purchased an SSD and several backup drives. But if your motherboard does not have a socket that matches your processor, your motherboard will not support the memory speed your RAM is rated for, your motherboard's PCIe slot layout will not accommodate your graphics card, or your motherboard will not have SATA or M.2 slots for your storage