The Southbridge chip is responsible for communication between I/O buses, such as PCI bus, USB, LAN, ATA, SATA, audio controller, keyboard controller, real-time clock controller, advanced power management, etc. These technologies are generally relatively stable, so the Southbridge chip may be the same in different chipsets, and the difference is only the Northbridge chip. So now the number of motherboard chipsets in the North Bridge chip is far more than the South Bridge chip. For example, the early Intel chipsets of different architectures Socket 7 430TX and Slot 1 440LX its Southbridge chip are used 82317AB, while the chipset Intel945 series chipset in the last two years are used ICH7 or ICH7R Southbridge chip, but can also be used with ICH6 Southbridge chip. What's more, some motherboard manufacturers produce a few products using the North and South Bridges are products of different chipset companies.
The development direction of the Southbridge chipset is mainly to integrate more functions, such as NICs, RAID, IEEE 1394, and even WI-FI wireless network, and so on.
The North Bridge chip is the most important component of the motherboard chipset that plays a dominant role, and is also known as the Host Bridge. Generally, the name of the chipset is named after the name of the North Bridge chip, for example, the North Bridge chip of Intel 845E chipset is 82845E, the North Bridge chip of 875P chipset is 82875P and so on. The Northbridge chip is responsible for contacting the CPU and controlling the memory and AGP data transfer within the Northbridge, providing support for the type and frequency of the CPU, the system's front-side bus frequency, the type and maximum capacity of the memory (SDRAM, DDR SDRAM, and RDRAM, etc.), the AGP slot, and ECC, etc. The Northbridge chip of the integrated chipset also integrates the display core. The Northbridge chip is the closest chip to the CPU on the motherboard, which is mainly due to the fact that the communication between the Northbridge chip and the processor is the closest, and the transmission distance is shortened in order to improve the communication performance. Because the north bridge chip data processing is very large, the heat generation is also increasing, so now the north bridge chip are covered with a heat sink to strengthen the heat dissipation of the north bridge chip, some motherboards will also be used with a fan to dissipate the heat of the north bridge chip. Because the main function of the North Bridge chip is to control the memory, and the memory standard and processor changes more frequently, so different chipsets in the North Bridge chip is certainly different, of course, this is not to say that the memory technology used is completely different, but the different chipsets North Bridge chip is certainly different in some places.
Because the AMD K8 core CPUs that have been released have integrated the memory controller inside the CPU, the northbridge chipset that supports the K8 chipset has become much simpler, and is even capable of adopting a single-chip chipset architecture. This may be a major trend, the function of the North Bridge chip will gradually be monolithic, in order to simplify the motherboard structure, improve the integration of the motherboard, perhaps the future mainstream chipset is likely to become the North and South Bridges in a single chip form (in fact, SIS released a number of single-chip chipsets in the old days).