Understanding your Motherboard - Internal components

Understanding your motherboard is about pointing out what the bits of your motherboard actually do, if you are not used to building or upgrading your own machine you will want to know the ins and outs of the motherboard. The motherboard is a very important piece of equipment in your PC as it is connected to everything. Anything of major importance is plugged straight into the board. Some things on a motherboard are meant to be changed and altered to suit your own specifications, other things are strictly to be left alone unless fully qualified. We will try to give you a brief bit of history if there is any on each of these parts and some specifications. 

We will start with the internal connecters and ports and then move on to the External ones. Internal connectors are for system builders and upgrading components. These connectors are for adding memory to the system, connecting Hard drives and optical drives as well as graphics cards and other expansion cards.

1 - Firewire header

Firewire is also known as IEEE 1394. It is basically a high performance serial bus for digital and audio equipment to exchange data. The technology preceded USB but yet is faster than any current USB port. Often used for transferring digital video to the PC straight from a digital camera. The FireWire header onboard means you can install a FireWire port on your machine. Again these cables are often supplied as an optional extra which you will need to check with the retailer to see if they are supplied with your board.

2 - PCI Express 16x slots

Now the most common slot for Graphics cards, the PCI Express 16x slots provides 16 separate lanes or data transfer. PCI express 1.0 slots offer a data transfer rate of 250MB/s the second generation of PCI express (PCI Express 2.0) offers twice the data rate at 500MB/s. Currently in development is PCI Express 3.0 which offers 1GB/s of data transfer. PCI Express 16x slots are also the basis for both SLI and Crossfire multi graphics card setups. With the increasing demands graphics cards are putting on systems, no less than a 16 lane slot will be good enough for any modern graphics card.

3 - PCI Express 1x Slot

Like the PCI Express 16x above the 1x slot uses exactly the same system but only has a single lane of serial data transfer. These slots are used for expansion cards that do no require the same amount of data transfer that a graphics card requires. You will usually find components such as tv tuners, network cards and sound cards make use of the PCI Express 1x slot. You will also notice the difference in size between the 1x and the 16x slots. The PCI Express 1x slot is noticeably smaller and easy to spot.

4 - Chipset - North Bridge (with heatsink)

The Motherboards chipset can be described as what sets it apart from other boards in its category. Different chipsets contain different features and components. A chipset is a number of integrated circuits built onto the board to provide specific functions e.g. one part of the chipset may be an onboard component such as a modem or sound chip. Other parts may be used to control the CPU functions. Most chipsets are designed to work with only one "class" of CPU although now many older chipsets support more than one type of CPU such as socket 7 which supports the Pentium, Cyrix 686, Cyrix MII, AMD K6 and K6-2. There are certain restrictions though to what type of processor a chipset can handle because of the logic that the CPU uses to access the memory and its cache etc. Since these chips are working harder with each generation, motherboard manufacturers have started to put heatsinks and active coolers (fans) on the main parts of the chipset to disperse some of the heat. For more information on chipsets see our What does a chipset do article.

5 and 8 - ATX Power connector

The standard ATX power connector, the cable for this will be coming from the PSU, a clip is normally provided to make sure you get them in the correct order. As a tip, don't try to push too hard if its stuck, check to see that it is in the correct way, I have seen plenty of power connectors where the pins have pushed out some of the connectors, these can be difficult to get back into place, so its best to be careful.

6 - CPU (Central Processing Unit) socket

All the CPU "sockets look very similar, however they are different in the way they have different amount of pins and in different layouts. There are currently two major CPU socket types PGA and LGA. PGA or Pin Grad Array uses a system of pins on the CPU and holes on the socket to line up and hold a CPU in place. The introduction of the ZIF (Zero Insertion Force) socket for PGA types allowed the CPU's to be lined up without any pressure on the CPU until a level is pulled down. LGA or Land Grid Array uses a system of gold plated copper pads that make contact with the motherboard. It is very important to read your motherboard manual to discover what types of CPU's you motherboard supports as most motherboards are aimed at a specific type of CPU.

7 - DIMM (Double Inline Memory Module) slots

DIMM's are by far and away the most used memory types in today's computers. They vary in speeds and standards however and they need to match up to what your motherboard has been designed to take. The four standards of DIMM's being used at the moment are SDR (Single Data Rate), DDR (Double Data Rate), DDR2 and DDR3. The speeds of memory can vary between 66Mhz to 1600Mhz.

9 - Motherboard controls

Not available on all motherboards, but some allow direct control of the motherboard via simple buttons. Power switch, error checking, CMOS clearing, passwords and more features can be accessed directly on the motherboard on some models.

10 - Chipset - South Bridge

When we talk about chipsets you mainly only ever hear about the North bridge. Even those into PC technology have a hard time naming the south bridges without looking them up. Names like Nforce 2 and KT600 are North bridges. The South Bridge does an important job as well. It handles things like the PCI bus, onboard Network and sound chips as well as the IDE and S-ATA buses.

11 - Serial ATA Connector

Serial ATA or more commonly seen as S-ATA is a new way of connecting your Hard Drives to your PC. S-ATA drives have the capability of being faster than the IDE counterparts and also have smaller thinner cables which help with the airflow of the system. S-ATA hard disks are fast becoming the norm for hard drive technology. Current motherboards feature both IDE and S-ATA connectors to facilitate all types of storage hardware.

12 - USB 2.0 header

As well as having USB ports on the rear of the motherboard, motherboard manufacturers often add a couple of USB headers so you can connect optional cables for extra USB ports. These cables are often supplied and you only need to add them on if you need the extra connectivity. USB 2.0 replaced USB 1.1 as a much faster solution. It is backwards compatible meaning all USB 1.1 devices will work in these new USB 2.0 ports.

13 - Motherboard Battery

The battery gives the board a small amount of power in order to store some vital data on your machine when the power is off. Data stored is that like the time and date so you don't have to reset them every time you boot the machine up. Motherboard batteries are usually long lasting Lithium batteries. Removing this can reset all the data on your machine including the BIOS settings, however not replacing this correctly can lead to irreparable damage to the motherboard. Only remove the battery if it is dead or if you can't have access any other way to resetting the data on your machine by use of the clear CMOS jumper or something similar.

14 - PCI (Peripheral Component Interconnect) slot

The PCI bus (not PCI express) is now an older technology and although the PCI slots are still available, they have decreased in number and are being replaced by the PCI Express 1x slots. Its unlikely that you will get a motherboard without a PCI slot at the moment due to the fact that a lot of components still use the standard PCI slot. It would be awkward to upgrade to a system without PCI slots as it may mean upgrading more components than you would like to,

15 - Floppy Drive Connector

More simple than the IDE connector you only have to remember to get the red line to pin 1 of the connector and the red line to pin 1 on the floppy drive, This port is only to be used with floppy drives. You may not have a floppy controller on your motherboard as its slowly being phased out as more people are using writable CD's and DVDs to transfer data, to store data and to use as boot up discs.

16 - IDE connector Not on Diagram

The connector to which you will insert an IDE cable (supplied with motherboard) IDE cables connect devices such as hard disks, CD Drives and DVD Drives. The current 4 standards of IDE devices are ATA 33/66/100 and 133. the numbers specify the amount of data in Mb/s in a max burst situation. In reality there is not much chance of getting a sustain data rate of this magnitude. Both the connectors and devices are backwards compatible with each other, however they will only run at the slowest rated speed between them. All IDE cables will come with a red line down one side, this red line is to show which way it should be plugged in. The red line should always connect to pin one of the IDE port. Checking your motherboard documentation should show you which end is pin one. In some cases it will be written on the board itself.

In the case of ATA 66/100/133 there is a certain order that you plug devices in, the cable is colour coded to help you get them in the correct order.

• The Blue connector should be connected to the system board

• The Black connector should be connected to the master device

• The Grey Connector should be connected to the slave device

17 - BIOS (Basic Input Output System) Chip - Not on Diagram

The BIOS holds the most important data for your machine, if configured incorrectly it could cause your computer not to boot correctly or not at all. The BIOS also informs the PC what the motherboard supports in terms off CPU etc. This is why when a new CPU is introduced that physically fits into a slot or socket you may need a BIOS update to support it. The main reason for this is that different CPU's use different logics and methods and so the BIOS has to understand certain instructions from the CPU to recognize it.

Now we will look at the External parts of the Motherboard >>