The motherboard is like a big city with many streets and highways that connect all of the buildings together. Instead of streets and highways, the motherboard uses tiny electrical paths to connect each component of the computer together. These paths are called "buses." The more buses that connect to a component, the faster it can operate. Larger buses are able to operate faster than smaller buses. Buses work just like highways. Wider highways and highways with more lanes are able to carry more traffic than smaller highways and highways with less lanes. Many cities have a freeway. A freeway is designed so that large amounts of traffic can move quickly from one place to another. The motherboard also has a "freeway." It is called the "front side bus," (or FSB). It is the most important bus on the motherboard, because it connects the processor to the main memory and the Northbridge chipset. The faster the FSB is, the faster the computer can operate, since the processor is constantly using the main memory to store and retrieve information. Sometimes the FSB is also called the "system bus." Below is a diagram showing the front side bus in red. Keep in mind that on an actual motherboard, each line representing the buses would actually consist of many electrical paths instead of just one.
Older motherboards had FSB speeds of 33MHz or even less. Many newer motherboards have FSB speeds of over 1000MHz. The motherboard in the picture above has a FSB speed that can be set to range from 66MHz to 133MHz.
Like a traffic cop, the Chipset, (2 chips on this motherboard), manages and directs the flow of data between each of the components. The BIOS is where the computer's settings are stored and changed. In the first picture of the slot 1 AOpen AX6B motherboard above, you can see most of the connecting slots, ports, and connectors. Some are labeled to show what they are. Motherboards are judged primarily by their chipsets and their front side bus speed. The type of BIOS and the type and amount of expansion slots are also other important things to consider. Below is a picture of the socket 939 Asus A8N-E, a more recent motherboard. It has a FSB speed equivalent to 2000MHz.
