Why is a Motherboard Important?

Motherboards are fairly complex instruments. Essentially, every computer has one and it plays many different roles.

So why is a motherboard important? Modern motherboards are basically the main building block of a PC. If CPU is the brain, then motherboard is the body of a computer.

Earlier computers didn’t have motherboards but they still worked using backplanes. These were passive boards that had no controllers or basic I/O chips installed.

Modern motherboards are active devices as they have multiple dedicated controllers for different components and interface such as for SATA, PCIe etc.

Computers today wouldn’t be what they are today without the motherboards as it serves as the main channel of communication between different devices.

Understanding the Motherboard

How Many PCie Slots Do I have
A motherboard is a complex circuit board with multiple chipsets and controllers for different interfaces.

Before we get into the nitty-gritty about what makes motherboards so important, it is essential to first understand what a motherboard is and what it does.

In a simple definition, a motherboard is the main circuit board on a computer. However, calling it a mere circuit board would be an understatement as they are far more specialized and have multiple active controllers for various subcomponents.

For most computers, having boards is not uncommon. The circuit boards installed on top of a motherboard are called daughterboards.

Also Read: Why Motherboard is Called Motherboard?

Graphics Card
A graphics card is a daughterboard that install on top of a motherboard.

From hard disk to graphics card, essentially, these connected components are nothing more than large specialized circuit boards that interface with the motherboard.

Also Read:

Various Motherboard Components and Systems

motherboard components and systems
Shows some of the subcomponents of a motherboard (older gen motherboard)

The image above gives some insight into the system and interfaces a motherboard offers.

From delivering power via the ATX Power Pin connectors to occupying expansion cards (daughterboards) on the PCI/PCIe slots, a motherboard is the foundation for any PC build.

The following are some of the essential interfaces and subcomponents that a motherboard features:

  • CPU Socket: for installing the CPU
  • Motherboard Chipset: The brain of the motherboard that relays information to and from CPU and the devices.
  • RAM Slot: For installing the memory; another essential component without which a computer would not work.
  • BIOS: Basic Input/Output System; A low-level operating system of the computer that speaks with the hardware at the most basic level. Helps you configure the hardware.
  • POST Check: Power On-Self Test; an essential verification check that determines if there is any fault with your hardware.
  • SATA Interface: One of the primary interfaces for connecting storage drives like hard disk drives and optical drives such as CD/DVD drives.
  • PCIe Interface: A critical interface for connecting HSIO (High speed Input/Output) devices. Supports a myriad of components including NVMe SSDs and Graphics Cards.
  • Ports i.e USB, video ports, peripheral connectivity ports etc
  • Network Connectivity: Most motherboards offer Ethernet connectivity, however, some also offer WiFi connectivity.
  • Sound Card: For audio

Also Read:

So Why is a Motherboard Important?

From above you can see that the role of a motherboard is fundamentally important for any PC. But lets reiterate what a motherboard does:

1. It Connects all the Other Components

Motherboard-Architecture 2
Shows how different controllers facilitate different components. Source: Wikiwand

The image above shows a basic-level architecture of a motherboard.

Other than connecting external components, the motherboard itself is filled with key components such as buses that carry signals from one component to the other.

Modern motherboard do not feature north and south bridge separately. Older motherboard had a separate north and south chipset for managing different interfaces.

However, modern motherboards only feature the South Bridge, which is just commonly referred to as the motherboard chipset.

Intel z490 chipset 2
A block diagram of a modern Intel Z490 chipset. Source: Intel.com

Also Read: What Makes a Motherboard Good?

2. Handles Synchronization of Various Tasks

clock and chipset

Located on the motherboard is a tiny quartz crystal. This component acts as the system clock. It ensures that all the other components on the motherboard are synchronized.

The clock sends out a signal after a given interval. This lets all the components know when to work and when not to. This prevents the many different components from sending a signal at the time when the components that are the intended destinations are not ready to receive it.

The other components only work when the clock is high and when it’s low they too remain dormant. This change happens many times in a second so it’s almost impossible to notice.

3. Contain the BIOS Chip

This motherboard has 2 BIOS chips. M_BIOS is the main BIOS; the B_BIOS is the backup BIOS if going back to factory default is ever needed.

One crucial chip found on a motherboard is a ROM chip for BIOS. BIOS  offers all the necessary instructions as well as settings for the computer to boot.

Without a BIOS chip, your computer would NOT start. BIOS stands for basic input/output system and it is the first program the processor accesses to get the computer started.

BIOS is also the key program that handles data flow from the input peripherals like keyboard, mouse, printer and the output peripherals like a monitor.

4. Contains the CMOS Battery and Chip

CMOS Battery

The CMOS battery is an important component as it helps keep the CMOS chip that maintains the system’s configurations up and running even when the computer is switched off.

The motherboard houses this battery. This lets you persist information such as important hardware settings and the system time. As a result, you may have noticed that the computer will tend to “remember” the time even when you shut it down.

This CMOS battery contained in the motherboard keeps the clock running even when the computer is off.

5. Handles Hardware Expansion

PCIe Expansion Slots

A PC would be nothing without expansion capability.

The expansion capability is primarily in two way i.e through PCIe interface and SATA interface.

Also Read:

6. Controls Power Supply to Components

How to Test Motherboard Without CPU 1

Being the main contact point for all the components of a computer, it also makes sense to have the main power supply connections run over the motherboard.

This allows all the board’s subsystems and other connected components to get access to power.

However, larger components like graphics cards and Hard Disk Drives require a separate power connection of their own from the Power Supply Unit.


motherboard VRM
Motherboard VRM

Motherboard VRM or Voltage Regulator Modules are important electrical subcomponents that bring the voltage down to a level the CPU can use.

VRMs essentially act like a step down transformer that bring down the 12V used by the motherboard to about 1.5V used by the CPU.

The more VRMs the motherboard has and the larger they are, the more efficient the motherboard would be at regulating the voltage for the CPU. Hence, CPU overclocking is heavily depended on specifications of the VRMs you have.

Also Read: What are Motherboard Power Phases and VRMs?

Short Buying Guide for a Motherboard

So you know that motherboard is an essential component for a PC build.

However, as a consumer, it is equally important to know what kind of specs on a motherboard are important for YOU!

Motherboard Chipsets

Motherboards are basically differentiated by the chipset they have. There are budget grade chipsets and then there are high end chipsets.

The following are some of the popular chipset series by both Intel and AMD for a consumer grade PC:

AMD Chipsets:

A Series, such AMD A520 Entry-Level chipset, for budget builds
B Series, such as B550 Mid Range chipset, for most gamers
X Series, such as X570 For Enthusiasts and high-performance PC builds

AMD 500 Series Chipset comparison

Intel Chipsets

H Series, such H310 For budget builds
B Series, such as B460 Very similar to H series, but are considered for mid-range builds
Z Series, such as Z590 For premium builds. The only Intel chipset that offers overclocking support.

What Separates One Chipset from the Other?

There are many factors that differentiate one chipset from the other and hence affect the price point as well:

CPU Socket: Defines Which CPU the Motherboard will Support

Newer chipsets feature support for newer CPUs. For instance, the older Intel Z390 offers support for the LGA1151 socket for 8th and 9th Gen CPU.

For installing the newer 10th or 11th gen Intel CPU, you will need the newer chipset such as the Z590 with the LGA1200 socket.

Also Read: LGA vs PGA CPUs

How Many PCIe Lanes and Ports the Motherboard has

The more PCIe lanes you have, the more expansion cards you would be able to install on your PC.

Motherboards have a limited amount of PCIe lanes. More premium chipsets offer more PCIe lanes.

In addition to that, cheaper motherboard have fewer PCIe expansion slots.

PCIe Version

Newer chipsets support newer PCIe version. Every PCIe version doubles the transfer speed compared to the previous generation.

With newer PCIe version, your system would be able to support much faster and efficient expansion cards.

For instance, if you have a PCIe v4.0 board, you would be able to install the much faster Gen 4 NVMe SSDs that can reach transfer speeds of about 5000 MB/s (compare this to an average HDD which has a transfer speed of about 200 MB/s).

Also Read: Which Motherboards Support PCIe 4.0?

Support for Multiple-GPU

Budget grade chipsets such as the AMD A series chipset, do not feature support for multiple-CPUs.


This is a very important factor for enthusiasts and gamer. Cheaper motherboards such as the A series from AMD and B and H series from Intel DO NOT support overclocking of CPUs.

Also Read: What is CPU Throttling?

So What Motherboard is Suitable For You?

For different users, different features of the motherboard would be important. But essentially the more boxes a motherboard check, the more expensive it would be.

For instance, if overclocking is important to you, then you will need to invest in a more expensive motherboard.

You have to gauge your requirements and your budget. If you are on a tight budget and are just looking for a simple motherboard, go for the budget series chipset. Just make sure it has the appropriate socket for your CPU.

Also Read: How Much is a Motherboard?

In Summary

Why is a motherboard important? Basically, motherboard is the orchestrator of every thing that goes around in a PC. It connects components and allows communication between them to occur.

In other words, the motherboard is the body, CPU is the brain and the rest of the components are the limbs of a PC.

Motherboards have a plethora of features that can separate them from each other. As a consumer you have to measure your requirements as well as your budget before purchasing the right model for you.

Also Read: Why RAM is Called Volatile Memory?

Photo of author


Atif Qazi
Atif Qazi is the founder of PCGuide101 and an expert in the computer peripheral industry with over two decades of experience. He has worked as a consultant for major companies and has a deep understanding of the inner workings of computer peripherals. He has a degree in Electrical Engineering and has served as a product manager and technical consultant. He is passionate about testing and evaluating the latest products to provide readers with reliable information.

Leave a Comment