What is southbridge (chipset)?
Southbridge is a reference to a chipset on a PC motherboard. It is a group of microchips designed for a single function and manufactured as a single unit. This chipset controls or manages input and output (I / O).
Examples of I / O interface connections controlled by the southbridge are USB, serial, IDE, and ISA. These are the motherboard's slower capabilities. It is located on the north bridge of the PCI bus and is not directly connected to the CPU, but rather connected to the CPU via the north bridge.
Southbridge is one of two chipsets commonly referred to as northbridge / southbridge. Northbridge is a chipset that controls the processor, memory, PCI bus, level 2 cache and AGP (Accelerated Graphics Port) functions.
The name comes from the original Intel motherboard design from 1991. This design had the PCI local bus (the backbone) in the middle and the CPU, memory / cache and other high performance critical components arranged above or to the north.
The less performance-critical components were located below or south of the PCI local bus. Bridges to these two sets of components from the backbone are often called the Southbridge and Northbridge, although the current architecture has replaced the PCI bus backbone with faster I / O buses.
Motherboard diagrams can generally refer to the southbridge as an I / O controller hub and the northbridge as a storage controller hub.