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Motherboard parts explained  | WePC

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Motherboards are as crucial to a PC’s operation as CPUs are, maybe even more so. Without a motherboard, your computer would be nothing more than an expensive paperweight. Budget or expensive, high-end or low-end, all motherboards aim to serve the same purpose. But what is a motherboard? And what do all its parts do? Good question, allow us to explain. 

motherboard parts explained

If you’re in the market for a new motherboard, we have a few ‘best of’ articles listed below to help you find a motherboard that’s right for you. 

What is a motherboard? 

Motherboards are arguably the most important component of your PC. A motherboard allows all your components to communicate with one another, such as your CPU, GPU, and RAM, all of these components would be rendered useless if you don’t have a motherboard to install them into.

It’s this communication that allows a computer to operate, if even one component isn’t pulling its weight, then the PC will not function properly and most likely fail altogether. 

Besides ensuring all of your components communicate in perfect synergy, your motherboard also houses a chipset that controls PC I/O interactions. This is designed specifically to work with a certain CPU architecture, whether that be Intel or AMD’s respective architecture. For example, Z690 chipsets belong to Intel and X670 chipsets belong to AMD. 

We’re operating under the assumption you have at least a slight understanding of what a motherboard is and how it works. So with that being said, let’s get into explaining the different parts of a motherboard. 

Motherboard parts explained 

Here are 16 of the most common and most important parts of a motherboard, below we will explain what they are and how they work. These parts are in no particular order. 

CPU socket

Mobo anatomy labels CPU Socket

A CPU socket is exactly what it says on the tin. The socket is located in the middle of the upper half of the motherboard. CPU sockets have what are called ‘lanes’ or ‘traces’ connected to them, although they themselves are a single connector between the CPU and motherboard. These connected lanes allow communication between the CPU and the rest of the components connected to the motherboard. 

Sockets are usually square or slightly rectangular in recent years with the release of 12th Gen Alder Lake Intel CPUs, which themselves are slightly rectangular. 

CPU sockets tend to come in two separate configurations in 2022, and those are LGA (land grid array) and PGA (pin grid array). Intel has been using LGA for years now, but with the introduction of AM5, AMD has announced it will be moving from PGA to LGA in favor of manufacturing costs and ease of installation. 

The socket is also designed to hold the CPU down with the aid of another component, the SAM (socket actuation mechanism) 


Mobo anatomy labels SAM

The Socket Actuation Mechanism comes in two forms on today’s mainstream motherboards, one for Intel and a separate one for AMD. This is because currently there are two types of socket pin configurations on the market (LGA and PGA). 

The socket actuation mechanism is designed to hold a CPU into its socket with some force, this is to ensure good contact between the lands or contact pins on the bottom of the CPU and the motherboard – we call this mounting pressure. 

Pressure is applied with the aid of a small leaver to the side of the socket which is clamped after the insertion of the CPU, holding it in place. 


Mobo anatomy labels CPU Socket 1

We mentioned the chipset earlier in the introduction, now it’s time to explain what a chipset actually is. 

A chipset resides on every motherboard and is one of the most important components of a motherboard. The chipset is the device that controls the communication between your CPU, RAM, and other components and peripherals. The chipset also determines how many devices such as USB devices your motherboard can support at any one time.

Chipsets are usually composed of one or more chips that feature controllers for not just hardware devices, but more commonly used peripheral devices too, such as keyboards and mice.

If you know anything about motherboards at all we’re sure you’ll be familiar with the terms ‘X670, Z690, B550’, and so on (or at least something of that nature) – these are the motherboard chipsets. The names can seem confusing at first but all you need to know is that they follow a specific hierarchy for both AMD and Intel processors, and the higher the number the better the chipset and the more it will support.

Here is the chipset hierarchy for both AMD and Intel, to give you a better understanding of what chipsets are better. 

AMD Chipset hierarchy

AMD Chipset Hierarchy

Intel Chipset hierarchy

Intel Chipset Hierarchy

Usually, the better chipsets are lettered towards the end of the alphabet, depending on whether it’s for AMD or Intel. X is better than B for AMD, it’s usually in reverse alphabetical order. So, an X570 chipset will be better than a B450 because the letter is later in the alphabet and the number is higher. 

RAM slots 

Mobo anatomy labels RAM slots

The acronym RAM stands for random access memory, and this is the volatile storage in which the computations and instructions are stored. RAM requires a slot in which to be seated. 

Ram slots are slots on the motherboard in which the RAM sits … Pretty self-explanatory. But that’s not all the RAM slots are responsible for delivering power to the RAM as well as transferring data to and from the RAM during normal PC operation. 

Some motherboards have more RAM slots than others, some have two and some have four. The reason you do not see any motherboards with an odd number of RAM slots is that RAM operates best in pairs. As the CPU switches which RAM stick it pulls from per cycle. 

The CPU also pulls from two specific ram slots before the other, that’s why a lot of motherboards have indication markings displaying which RAM slots you should fill first. 

PCI / PCIe slots 

Mobo anatomy labels PCI Slots

Motherboard PCIe slots are where you’d expect to find the average GPU or network card in a PCI slot. PCIe stands for peripheral component interconnect express, with PCI just standing for peripheral component interconnect. 

Motherboard PCIe slots, much like RAM slots, have lanes that connect to the CPU. Lanes and PCIe slots improve generationally, with the newest PCIe technology being generation five. Both speed and bandwidth improve with each PCIe generation, allowing GPUs and other peripheral devices to output more data at a greater speed, and have it all processed faster thanks to the faster lane speeds. 

There’s a total of 24 PCIe lanes connected to the CPU in modern motherboards, 16 of them are used for the Primary PCIe slot, 4 of the lanes for storage, and 4 for the chipset. However, modern motherboards have the technology to switch PCIe lanes on the fly when they’re not needed, to make sure speed and bandwidth is being added where it’s needed the most. 

These slots are often referred to as ‘expansion slots’ and this is from the days of adding Soundblaster cards to older PCs to get an expanded audio experience. These slots do exactly what they say on the tin, and that’s to connect micro-boards that expand your PC’s capabilities.  

M.2 slots

Mobo anatomy labels m.2 slots

NVME M.2 slots are technically PCIe slots as they use the same communication system and PCIe lanes to communicate with the CPU as GPUs do. M.2 storage technology has taken off in recent years with the most advanced version of the storage technology being PCIe Gen 5. 

These small slots are located just below the CPU socket in most cases and are capable of transferring data at blisteringly fast speeds. The most recent Gen 5 M.2 SSD features read speeds up to a massive 13000MB/s, with write speeds only slightly lower at 12000MB/s. For context, these speeds are more than double the fastest Gen 4 M.2 SSDs on the market. 

To accomplish speeds like this the M.2 slot has to be connected to the CPU directly via PCIe lanes, there are 24 lanes in total and four are dedicated to PCIe storage solutions. The rest are delegated between GPU and chipset. 

Motherboard I/O

Mobo anatomy labels IO

Motherboard I/O stands for Input-Output, and it’s a pretty simple mechanism allowing your motherboard to connect to and use devices that do not belong to itself. I/O is an all-encompassing term for the connectivity integrated into your motherboard, USB, Audio jack, HDMI, PS2 (if you’re old school), and optical are all motherboard I/O. 

The purpose of having all this connectivity is to extend the capabilities of your motherboard, for example, a mouse and keyboard, which are essential to PC usability, are both classed as I/O – specifically peripheral devices. 

It’s not just the output section of the motherboard that you can find I/O, it’s actually built into your PC case too. The USB slots on the front of your case are attached to the motherboard, acting as extended I/O. 


Mobo anatomy labels VRMs

VRMs are incredibly complicated and deserve their own article, but we’ll try to keep things simple for now.

Motherboard VRMs play an integral part in PC operation, and that’s voltage regulation. VRM stands for Voltage Regulation Module and it does pretty much exactly what it says on the tin. The VRM is responsible for delivering consistent, clean power to the CPU at the required voltage. A low-quality VRM can cause a whole host of problems such as shutting down under load and poor overclocking capabilities. 

A PSU supplies 12 volts of power to the motherboard. However, sensitive components, like CPUs, can’t handle this level of voltage. That’s where the VRM comes in, by stepping down the incoming 12-volt power supply to 1.1-volts and sending the power where it’s needed. 

Most modern motherboards ship with multi-stage VRMs, and these differ slightly from the standard single-stage VRMs. The way multi-stage VRMs work is that when they receive the power they distribute it evenly amongst themselves. The reason this is important is to allow each stage of every VRM to supply a small amount of power individually to the CPU, rather than the full load over single-stage VRMS. 

By supplying small amounts of power pre-stage, the VRMs improve heat dissipation among themselves, and can also help power higher TDP CPUs more safely.