If you were comparing a computer to a person, the motherboard would be the spine or central nervous system that allows all the components to work together and communicate. The motherboard connects the processor, RAM, hard drives, peripheral cards, and connections to the printers and other external devices. If it touches the computer, it has to interact with the motherboard.
Motherboard Components
Aside from the most recognizable pieces attached to the motherboard, otherwise known as the system board, those pieces being the processor, RAM and network/video cards, there are other parts attached that are critical to the operation of a computer.
One that resides on most motherboards is the L2 cache, or level 2 cache. Cache memory speeds up performance by storing frequently used code and instructions for the processor. L1 cache is usually found on the processor.
Also on the motherboard are the motherboard chipsets, referred to as the North and South Bridges. Each chipset is responsible for management of specific components, for example the South Bridge manages requests from PCI and IDE components.
Smaller motherboard components include the CMOS battery, which is a CR2032 battery that can be found at any office supply store, and the BIOS. The BIOS contains information for the configuration of the basic components as well as the information for booting up the PC, such as boot order.
On most motherboards, you will also have your PCI/AGP slots, built in network and audio cards, and built in USB/Firewire. When an integrated part of a motherboard has issues, it usually results in the motherboard needing to be replaced.
Motherboard Forms and Factors
Motherboards change as technology advances. In the beginning, there were AT and Baby AT form factors. AT stands for Advanced Technology. These forms served the first series of desktops and servers and were limited in the amount of components that could be put onto the system board.
Then came low profile and new profile extended or LPX/NPX. These were designed around the concept of reducing the computers footprint on the desk. This led to the smaller desktops we see today.
The most common motherboard form now seen is the ATX, and its spin offs Baby ATX and microATX. These system boards tend to be all-in-one units, containing sound, video, network, and USB/Firewire connections. It is a cost savings to have it all integrated but the downside is if one piece fails, the whole motherboard will have to be replaced, rather than just the individual components.
BUS Architectures
The expansion slots on motherboards allow you to add cards to expand the video, audio and media capabilities. The most common bus architectures that are used today are PCI/PCIX, PCI-E and AGP. Most peripherals you can buy will fit into one of these three categories. The difference between them is BUS speed, PCI being the slowest, PCI-E the fastest, and AGP right in the middle.
On older boards you will find ISA, VESA, MCA, EISA, and in laptops PCMCIA. Most are now outdated and rarely supported, and parts to replace the components are scarce.
Common Problems
From experience, the two most common issues with motherboards are connections and environmental. If you encounter issues with components, ensure they are connected properly to the motherboard.
Environmentally, dust is a killer, and making sure you clean the inside of the computer regularly will extend the life of the motherboard and its parts considerably.
Motherboards are a key component of the computer and though seemingly complicated, can be easily replaced if the need arises.
