Computer Motherboard, a Peek Inside a PC.

What is a Computer Motherboard?

Many people in this era are frequent computer users or interact with a computer in one way or another. It is, however, noted that most computer users shy away from understanding how a computer works and the various components of a computer. Today we take time to look into a computer motherboard and try to demystify it.

A computer motherboard, or mainboard, is the main circuit board inside a pc to wich all internal and external devices are connected, either plugged directly to the motherboard or are connected via various types of cables.

When you see inside a desktop computer case and look at all the internal components, you will see a large circuit board with some smaller circuit boards attached at right angles to the motherboard, these are the components that are plugged to the motherboard directly such as the graphics card, network card and RAM modules.

The internal components that are connected via cables are usually the hard disk drive, DVD ROM, card readers, front audio connectors, cooling fans, power switch, front USB ports.

You will see mounted somewhere near the top middle of the motherboard a large fan and cooling fins, underneath this is where the PC’s central processor unit (CPU) is housed, you won’t be able to see the CPU because the cooling block is mounted directly on it. The CPU is a thin square-shaped component that is plugged directly into the motherboard via a socket.

Form Factor.

Motherboards come in various sizes known as form factors and some of these are;

• Pico ITX
• Nano ITX
• Mini ITX
• Mini ATX
• Micro ATX
• Standard ATX

You will need to pay attention to the form factor when selecting some components for a pc as it is the type of form factor that will determine if the component will fit or not. For example, a motherboard that is in the form factor of a Standard ATX will not fit inside a pc case that is of the Mini ATX form factor, it would be too large.

However, some standard ATX PC cases may be able to accommodate smaller form factor motherboards, you would need to look at the specs before making your purchase.

Chipset.

The motherboard contains a chipset which dictates the kind of CPU you will install on it. The type of chipset a motherboard has ensures that the CPU will work to a given performance level, and this informs how one selects a motherboard depending on the level of performance required for a given computer.

You will also need to know the socket type of the motherboard when choosing, replacing or upgrading your CPU, as a mismatch here will result in the CPU not fitting on to the motherboard socket.

Connectors on the Computer Motherboard.

There are a good number of connectors on the motherboard whose primary function is to interconnect components to the motherboard. These can be categorized into two broad categories, internal and external connectors.

Internal Connectors.

The internal connectors allow you to connect items that are mounted inside the case such as the serial ATA connectors (SATA), these connect the hard drives and CD/DVD ROM drives to the motherboard via cables known as SATA cables, these are tape-like cables with ‘L’ shaped connectors as shown in the image below.

There are other various connection points on a computer’s motherboard that will allow you to connect to ports on the pc case and these are the front audio ports, front USB ports and various panels such as memory card readers.

In the above image, you can clearly see the front audio with SPDIF, the front firewire, a system fan and front USB3 and USB2 connectors on the motherboard. When connecting a device be careful to have the connector in the correct orientation and not to bend the pins.

External Connectors.

At the back of a PC, you will see quite a few ports grouped together in a rectangular-shaped panel, this is known as the back panel. These are the various ports that are used to connect external peripherals that are permanently connected to the PC, such as the keyboard, mouse, a printer, scanner, webcam etc, and these are plugged directly to the computer motherboard.

The motherboard back panel is not universal and will only fit the make and model of the motherboard that it was made for, so if you are replacing your motherboard make sure that it is supplied with the correct back panel.

Expansion Slots.

In the bottom left-hand corner of the motherboard, you will notice some slots, these are known as expansion slots and are in the form of PCI Express (PCIe). One or two of these may be occupied by a graphic card and a networking card and some will be empty. The idea here is so that you can add more functionality to your pc.

The top slot is generally used for the graphic card which in turn is connected to your monitor. If you want to upgrade your graphics card you can easily remove it and replace with a new one. Just remove one screw from the back of the PC and release the locking clip and the card will pop out.

You can clearly see the different locking mechanism that are used on this board, these also vary from make to make and model to model. The various slots on the motherboard run at different speeds and are marked on the board itself or in the manual that comes with the motherboard.

I hope that I have explained in simple terms what a computer’s motherboard is and how it works and how the internal and external components connect to it to make the PC function. If you have any questions or comments please feel free to ask in the box below.