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Parts of computer Motherboard and their Function Explained (Updated 2022)

The computer motherboard also knows as the printed circuit board is the foundation of a computer that allocates power and allows communication to and between the CPU, RAM, and all other computer hardware components. There are multiple types of motherboards, designed to work with specific types of processors and memory. And almost every major component (such as CPU, Memory, expansion slots and more) that crucial for the functioning of the computer is attached to the motherboard. In this post, you will learn different parts of computer motherboard and its function explained one by one.

Which is the most important component of a computer system? Technically Each and every component is important, where processor plays an important role in the computer but it cant operate without memory or power supply this is why each and all the components of a computer are very important as they are there are there for a reason.


Parts of computer motherboard (explained)

When you open up your desktop computer and take out the motherboard, you would probably get pretty confused about all the different parts. Depending on the make and model of your computer, it might look something like this.

Parts of computer motherboard

CPU socket on motherboard

The CPU Central Processing Unit is the most important part of your Computer. It also call the brain of the computer that responsible for fetching, decoding, and executing program instructions as well as performing mathematical and logical calculations. And the CPU socket is where your CPU (processor) is installed.

CPU socket on motherboard

Memory Slot on motherboard

RAM (Random Access Memory) also called computer memory is another crucial part of the computer. It’s volatile that temporarily store dynamic data to enhance computer performance while you are working and it loses its contents once power is turned off. Well, the memory slots are where we insert the RAM. Most computer motherboards have two to four memory slots, which determine the type of RAM used with the computer. And the most common types of RAM are SDRAM and DDR for desktop computers and SODIMM for laptop computers, each having various types and speeds.

RAM slots on motherboard

Basic Input/Output System (BIOS)

BIOS stands for Basic Input/Output System is where all the information and settings for the motherboard are stored. And It can be accessed, updated, and modified via the BIOS mode. BIOS is essentially the link between the computer hardware and software in a system. The BIOS is stored on a ROM chip because ROM retains information even when no power is being supplied to the computer and used during the startup routine (boot process) to check out the system and prepare to run the hardware.

The CMOS Battery

Complementary Metal Oxide Semiconductor also know as CMOS battery is what’s responsible for keeping all the information intact when the entire system is shut down. And all motherboards include a small separate block for CMOS which are kept alive by a battery (known as a CMOS battery) even when the PC’s power is off. This prevents reconfiguration when the PC is powered on. Again the CMOS battery is removable that can be removed to reset the BIOS after a failed update or if you overclock your RAM beyond its capabilities.

CMOS battery on motherboard

The Computer Cache Memory

Cache memory is a small block of high-speed memory (RAM) that that acts as a buffer between RAM and the CPU. It holds frequently requested data and instructions so that they are immediately available to the processor on demand.

Well, Most CPUs have an internal cache memory built into the processor that is referred to as Level 1 or primary cache memory. And this can be supplemented by external cache memory fitted on the motherboard that is the Level 2 or secondary cache.

Cache memory on motherboard

PCI slots – The Expansion Buses

PCI stands for Peripheral Component Interconnect and expansion bus is an input/output pathway from the CPU to peripheral devices. These are the slots that allow inserting expansion cards such as graphics card, sound card, LAN card or several other functional computer parts. PCI is the most common expansion bus in a PC and other hardware platforms. Buses carry signals such as data, memory addresses, power, and control signals from component to component. Other types of buses include ISA and EISA.

PCI slots on motherboard


On older computer motherboards, you found Integrated Drive Electronics (IDE) sots. These are the standard interface for connecting a motherboard to storage devices such as hard drives and CD-ROM/DVD drives. But now the latest motherboards make use of SATA technology. A serial advanced technology attachment (serial ATA, SATA or S-ATA) is a computer bus interface used to connect host bus adapters (disk drive controllers) with mass storage devices like optical drives and hard drives.

SATA slots on motherboard

The Computer Chip-sets

A chipset is a group of small circuits that coordinate the flow of data to and from a PC’s key components. These key components include the CPU itself, the main memory, the secondary cache, and any devices situated on the buses. A chipset also controls data flow to and from hard disks and other devices connected to the IDE channels.

A computer has got two main chipsets:

  1. The NorthBridge (also called the memory controller) is in charge of controlling transfers between the processor and the RAM, which is why it is located physically near the processor. It is sometimes called the GMCH, for Graphic and Memory Controller Hub.

  2. The SouthBridge (also called the input/output controller or expansion controller) handles communications between slower peripheral devices such as USB, audio, serial, the system BIOS, the ISA bus, the interrupt controller and the IDE channels. It is also called the ICH (I/O Controller Hub). The term “bridge” is generally used to designate a component that connects two buses.

North bridge South bridge on motherboard

Input/Output Ports on motherboard

These ports are located at the back of the computer and are often color-coded.

  1. Microphone- Pink 3.5mm jack port

  2. Speakers and Headphones / Headsets / Earbuds- Bold green 3.5mm jack port

  3. Monitor- Older motherboards are equipped with a solid blue VGA port at the back, but newer motherboards use the HDMI and black or white DVI port as standard

  4. Ethernet network cable- Colorless port

  5. Keyboard and Mouse- PS/2 port (Keyboard- purple; Mouse- green)

  6. USB devices- USB 2.0 colorless port; USB 3.0/3.1 solid blue port (Yes, VGA ports are a similar color, but this only goes to show how outdated VGA is)

  7. Some modern motherboards feature USB C type connections

IO ports on motherboard

CPU Fan – a fan located on top of a computer processor. It helps to pull and blow hot air off the processor, helping keep it cooler. Power Supply Fan – a fan located inside a power supply.

Pro Tips: When you start your Computer you may hear a beep code these are the audio signals given out by a computer to announce the result of a short diagnostic testing sequence the computer performs when first powering up (called the Power-On-Self-Test or POST). When you power on your computer, it has to test major devices such as RAM, Processor, Keyboard, and Drives among others. If any of the devices are faulty, you will receive a beep sound indicating which device has a problem.

Here a video explain, what are the parts of motherboard and their function

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