Motherboard chipset is master of all the communication between CPU, the memory, and the local bus. Your CPU drives the decision on which chipset to buy and use. A fast chipset would allow efficient data transfers and power management. Therefore, the chipset is well-deserved the most important part of a motherboard. Nowadays quality motherboard often use the chipsets like 975X, 975P offered by Intel Corp, or chipsets like C51G, nForce4 SLI/SLI X16 supplied by NVIDIA Corp.

Motherboard chipset is normally composed of the southbridge chip and the northbridge chip.

The northbridge is mainly responsible for the data transmission between the CPU, the memory and the AGP ports, and also connects with the southbridge through specific data channels. The encapsulation of the northbridge originally used BGA as its package mode, now the encapsulated mode of the Intel northbridge has changed into FC-PGA package, but the northbridge designed for AMD processor is still using a traditional BGA package.

Compared with the northbridge, the southbridge chip mostly takes charge the communication between IDE devices, PCI devices, audio devices, network devices and other I/O devices. Till now, the southbridge is still a BGA package.

Additionally, except for the conventional classification of the southbridge and the northbridge, now we also can see an all-in-one design in some NVIDIA and SiS chipsets. This plan integrates the northbridge and the southbridge into one chip, which has a deep meaning in cost saving and improving the competitiveness of similar products, however it has not been widely popularized.