Serial ATA (SATA, abbreviated from Serial AT Attachment) is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives.
SATA host adapters and devices communicate via a high-speed serial cable over two pairs of conductors. In contrast, parallel ATA (the redesignation for the legacy ATA specifications) uses a 16-bit wide data bus with many additional support and control signals, all operating at a much lower frequency. To ensure backward compatibility with legacy ATA software and applications, SATA uses the same basic ATA and ATAPI command sets as legacy ATA devices. SATA has replaced parallel ATA in consumer desktop and laptop computers.
SATA continues to advance and has been combined, over time, with other interfaces to assist in higher throughput capacities.
Small Computer System Interface (SCSI) is a set of standards for physically connecting and transferring data between computers and peripheral devices.
SCSI is derived from "SASI", the "Shugart Associates System Interface", developed circa 1978 and publicly disclosed in 1981. A SASI controller provided a bridge between a hard disk drive's low-level interface and a host computer, which needed to read blocks of data.
SCSI is available in a variety of interfaces. The first was parallel SCSI (also called SCSI Parallel Interface or SPI), which uses a parallel bus design. Since 2005, SPI was gradually replaced by Serial Attached SCSI (SAS), which uses a serial design but retains other aspects of the technology. Many other interfaces which do not rely on complete SCSI standards still implement the SCSI command protocol; others drop physical implementation entirely while retaining the SCSI architectural model. iSCSI, for example, uses TCP/IP as a transport mechanism, which is most often transported over Gigabit Ethernet or faster network links.
In computer hardware, a host controller, host adapter, or host bus adapter (HBA) connects a computer, which acts as the host system, to other network and storage devices. The terms are primarily used to refer to devices for connecting SCSI, Fibre Channel and SATA devices. Devices for connecting to IDE, Ethernet, FireWire, USB and other systems may also be called host adapters.
Host adapters can be integrated in the motherboard or be on a separate expansion card.
Peripheral Component Interconnect (PCI) is a local computer bus for attaching hardware devices in a computer and is part of the PCI Local Bus standard. The PCI bus supports the functions found on a processor bus but in a standardized format that is independent of any particular processor's native bus.
The PCI specification has more recently been superseded by the PCI Express (PCIe).
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards. It is the common motherboard interface for personal computers' graphics cards, hard drives, SSDs, WiFi and Ethernet hardware connections. PCIe has numerous improvements over the older standards, including higher maximum system bus throughput, lower I/O pin count and smaller physical footprint, better performance scaling for bus devices, a more detailed error detection and reporting mechanism (Advanced Error Reporting, AER), and native hot-swap functionality. More recent revisions of the PCIe standard provide hardware support for I/O virtualization.
"Serial ATA" by Multiple Contributors, Wikipedia is licensed under CC BY-SA 3.0
"SCSI" by Multiple Contributors, Wikipedia is licensed under CC BY-SA 3.0
"Host adapter" by Multiple Contributors, Wikipedia is licensed under CC BY-SA 3.0
"Peripheral Component Interconnect" by Multiple Contributors, Wikipedia is licensed under CC BY-SA 3.0
"PCI Express" by Multiple Contributors, Wikipedia is licensed under CC BY-SA 3.0