The south bridge is a hardware component of a PC motherboard (also called motherboard or mainboard ). It is close to the PCI slots to make an electrical connection to the shortest possible path. The Southbridge is beside North Bridge, an important part of the mainboard. The two chips can be also referred to as the chipset.
About the South Bridge chip data transfer and control data between peripheral devices takes place ( PCI bus, ISA bus, ATA, etc. ) and other interfaces. In addition, a portion of the periphery is in modern motherboards often already integrated on the Southbridge, for example, the USB controller. South and North Bridge also communicate either via PCI or PCI-X, a proprietary interface (such as VIA's V-Link ) or free industry standards such as the HyperTransport interface of the HT consortium. In general, the chips of the Southbridge are slower than the northbridge, and are therefore used for the slower work such as power management (eg control of standby mode), interrupt controller, BIOS EEPROM, network controllers, etc.. Furthermore, it is entrusted with the control of the USB ports.
In the Intel terminology, the Southbridge is called I / O Controller Hub (ICH) today. In a narrower sense it refers to the Intel 82801 chip.
When Nvidia nForce4 chipset for AMD processors, the Southbridge is directly integrated into the Northbridge in many versions. This is possible because the Northbridge memory controller contains no more, as this is already integrated in the Athlon 64 CPU. The versions for Intel processors but the classic division into North and South Bridge is reused.