One of the main and one of the most important components you'll find on the motherboard is the chipset Older motherboards were designed with a lot of different chips scattered all over the motherboard There were chips for different things, like chips for bus controllers, memory controllers, keyboard controllers, and so on so they had a lot of different chips controlling different functions on the motherboard. So as technology progressed, computer engineers decided to reduce the number of chips and have them more in a centralized location So instead of having these different chips scattered all over the motherboard, controlling different functions, they reduced the number of chips to do the same job and condense them to only a few chips, or what's now called a chipset and that's what a chipset is, a chipset is a smaller set of chips that has replaced a larger amount of chips and the chipset's job is to control data flow between the CPU, the peripherals, bus slots, and memory So all of the different parts of the computer communicate with the CPU through the chipset The chipset basically consists of two chips one is called the northbridge and the other is called the southbridge The northbridge is located in the upper or northern part of the motherboard, providing you're looking at the motherboard in the upright position It's located near the CPU and is directly connected to the CPU It's also directly connected to the memory and the AGP and PCI-Express slots So in order for the CPU to communicate with the memory and the AGP or PCI-Express bus, it has to go through the northbridge first So the northbridge acts like a communication middleman between the CPU, AGP or PCI-Express, and memory The other chip is called the south bridge and the southbridge is located at the bottom or southern portion of the motherboard, near the PCI bus slots The southbridge connects to the PCI bus slots, SATA, and IDE connectors, and USB ports. So the southbridge is responsible for the lower portion of the motherboard While the northbridge is responsible for the upper portion There is no direct connection between the CPU and the lower portion of the motherboard So if the PCI, USB, IDE, or SATA ports needed to communicate with the CPU, the information has to go through the south bridge and then up through the northbridge and then to the CPU The northbridge is faster than the southbridge, and that's because the CPU, the PCI-E, AGP, and memory are the most used and most important components of the motherboard.
So they need to operate at the highest speeds possible The slower southbridge communicates with the PCI bus, SATA, and IDE connectors, and USB ports and they don't need to be as fast as the other components So basically the higher speed components are connected to the northbridge and the slower components are connected to the southbridge Now both the north and southbridge make these connections to various parts of the motherboard using pathways called a bus and a bus is simply a set of pathways that allows data and signals to travel between components on the motherboard the motherboard contains several kinds of buses that vary in speed and bandwidth. so for example if a bus speed is set to operate at 66 MHz then that means that, that particular bus can send data at 66 million cycles per second. the higher the bus speed, the faster the computer can send data which improves the performance of the computer A motherboard's bus speed generally refers to the speed of the front side bus The front side bus is the connection between the CPU and the northbridge chipset.
