Форм-факторы материнских плат (Basic PC architecture)

The southbridge on AMD mainboards houses the AMD SATA controller, AMD USB2 controller, the controller for the legacy PCI bus and hosts and several single lane PCI express connections. It also connects to the onboard audio chip on the mainboard and the onboard network controller(s) on the mainboard as well as the legacy I/O controller chip which houses things like the old parellel printer port, serial port and PS/2 mouse/keyboard connectors. The way these items are wired up to the southbridge is either via an internal PCI bus connection or an internal PCI express connection. To the operating systems these devices appear the same way as when they would be on an expansion card in a PCI or PCI express slot.