Topology
SATA uses a point-to-point architecture. The physical connection between a controller and a storage device is not shared among other controllers and storage devices. SATA defines multipliers, which allows a single SATA controller to drive multiple storage devices. The multiplier performs the function of a hub; the controller and each storage device is connected to the hub.
Modern PC systems have SATA controllers built into the motherboard, typically featuring 2 to 8 ports. Additional ports can be installed through add-in SATA host adapters (available in variety of bus-interfaces: USB, PCI, PCI-e.)
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