PCH is an integrated south bridge of Intel Corporation, and the product name of PCH is Intel P55. PCH chip has all the functions of the original ICH and the management engine function of the original MCH chip, so it is better to call it North Bridge.
South bridge chip is the most important part of motherboard chipset except North bridge chip. Generally located under the motherboard, far away from the CPU slot and close to the PCI slot. This layout is based on the principle that there are many I/O buses connected to it, being far away from the processor is beneficial to wiring, and it is easier to realize the wiring of equal signal lines.
Southbridge chip is responsible for the communication between I/O buses, such as PCI bus, USB, LAN, audio controller, keyboard controller, real-time clock controller and advanced power management. Different South Bridge chips differ greatly in function.
The south bridge chip is responsible for the communication between I/O buses. These technologies are generally stable, so the South Bridge chip may be the same in different chipsets, but the difference is only the North Bridge chip. Therefore, the number of north bridge chips in the motherboard chipset is far more than that of south bridge chips.
For example, early Intel chipsets with different architectures, such as 430TX of Socket7 and 440LX of Slot 1, all used 823 17AB for their South Bridge chips. In recent two years, ICH7 or ICH7R southbridge chips have been used in Intel945 series chipsets, but they can also be matched with ICH6 southbridge chips.
What's more, the North-South Bridge used in a few products produced by some motherboard manufacturers is the products of different chipset companies.