Connectors and cables present the most visible differences between SATA and parallel ATA drives. Unlike PATA, the same connectors are used on 3.5-inch SATA hard disks (for desktop and server computers) and 2.5-inch disks (for portable or small computers). Standard SATA connectors for both data and power have a conductor pitch of . Low insertion force is required to mate a SATA connector. A smaller mini-SATA or mSATA connector is used by smaller devices such as 1.8-inch SATA drives, some DVD and Blu-ray drives, and mini SSDs. A special eSATA connector is specified for external devices, and an optionally implemented provision for clips to hold internal connectors firmly in place. SATA drives may be plugged into
SAS controllers and communicate on the same physical cable as native SAS disks, but SATA controllers cannot handle SAS disks. Female SATA ports (on motherboards for example) are for use with SATA data cables that have locks or clips to prevent accidental unplugging. Some SATA cables have right- or left-angled connectors to ease connection to circuit boards.
Data connector The SATA standard defines a data cable with seven conductors (three grounds and four active data lines in two pairs) and 8 mm wide wafer connectors on each end. SATA cables can have lengths up to , and connect one motherboard socket to one hard drive. PATA
ribbon cables, in comparison, connect one motherboard socket to one or two hard drives, carry either 40 or 80 wires, and are limited to in length by the PATA specification; however, cables up to are readily available. Thus, SATA connectors and cables are easier to fit in closed spaces and reduce obstructions to
air cooling. Some cables even include a locking feature, whereby a small (usually metal) spring holds the plug in the socket. SATA connectors may be straight, upward-angled, downward-angled, leftward-angled, or rightward-angled. Angled connectors allow lower-profile connections. Downward-angled connectors lead the cable immediately away from the drive, on the circuit-board side. Upward-angled connectors lead the cable across the drive towards its top. One of the problems associated with the transmission of data at high speed over electrical connections is described as
noise, which is due to electrical coupling between data circuits and other circuits. As a result, the data circuits can both affect other circuits and be affected by them. Designers use a number of techniques to reduce the undesirable effects of such unintentional coupling. One such technique used in SATA links is
differential signaling. This is an enhancement over PATA, which uses
single-ended signaling. The use of fully shielded, dual
coax conductors, with multiple ground connections, for each differential pair improves isolation between the channels and reduces the chances of lost data in difficult electrical environments. File:SATA-cable.jpg|SATA data cable File:2.5-inch SATA drive on top of a 3.5-inch SATA drive, close-up of data and power connectors.jpg|SATA connectors on 2.5 and 3.5-inch hard drives, with data pins on the left and power pins on the right. The two different pin lengths ensure a specific mating order; the longer lengths are ground pins and make contact first. (The cable side has similar variations to achieve three levels of mating order.) File:SATA3-TwinAxCable.jpg|Cut-open SATA cable showing the two foil shielded differential pairs File:SATA data and power conectors - close.jpg|Close-up of SATA data and power connectors There are
SATADOM variants of the connector merging power supply into the 7-pin connector, saving space in industrial setups. The "pin 7" variation repurposes pin 7 for +5V power. The "pin 8" variation repurposes two unnumbered shielding pins for power GND and +5V.
SATA power connectors Standard power connector (15 pins) SATA specifies a different
power connector than the four-pin
Molex connector used on
Parallel ATA (PATA) devices (and earlier small storage devices, going back to
ST-506 hard disk drives and even to floppy disk drives that predated the IBM PC). It is a wafer-type connector, like the SATA data connector, but much wider (fifteen pins versus seven) to avoid confusion between the two. Some early SATA drives included the four-pin Molex power connector together with the new fifteen-pin connector, but most SATA drives now have only the latter. The new SATA power connector contains many more pins for several reasons: • 3.3 V is supplied along with the traditional 5 V and 12 V supplies. However, very few drives actually use it. • Pin 3 in SATA revision 3.3 has been redefined as PWDIS and is used to enter and exit the POWER DISABLE mode in line with SAS-3. If Pin 3 is driven HIGH (2.1–3.6 V max), power to the drive circuitry is cut. Pins 1 and 2 are redefined as retired and no longer used for any purpose. Drives with this feature enabled do not power up in systems designed to SATA revision 3.1 or earlier, because Pin 3 driven HIGH prevents the drive from powering up. There is also a specification for transmission of drive temperature and other status values with activity signal pulses routinely used to make LED blink. Passive adapters are available that convert a four-pin
Molex connector to a SATA power connector, providing the 5 V and 12 V lines available on the Molex connector, but not 3.3 V. There are also four-pin Molex-to-SATA power adapters that include electronics to additionally provide the 3.3 V power supply. However, most drives do not require the 3.3 V power line. Just like SATA data connectors, SATA power connectors may be straight, upward-angled, or downward-angled.
Slimline power connector (6 pins) SATA Slimline Powercable.jpg|A six-pin slimline SATA
power connector SATA connector Slimline CD-ROM.jpg|The back of a SATA-based slimline optical drive The power connector is reduced to six pins so it supplies only +5 V (red wire), and not +12 V or +3.3 V. Pin 1 of the slimline power connector, denoting device presence, is shorter than the others to allow hot-swapping. Note: The
data connector used is the same as the non-slimline version. Low-cost adapters exist to convert from standard SATA to slimline SATA. SATA 2.6 is the first revision that defined the
slimline power connector targeted for smaller form-factors drives, such as laptop
optical drives.
Micro connector Micro SATA pin-out on Toshiba MK1216GSG 20131114.png|A 1.8-inch micro SATA hard drive with numbered data and power pins on the connector 2008 Intel Developer Forum Taipei Showcae Samsung muSATA 128GB SSD.jpg|
Samsung 128 GB micro SATA
solid-state drive The micro SATA connector (sometimes called uSATA or μSATA) originated with SATA 2.6, and is intended for 1.8-inch hard disk drives. There is also a micro data connector, similar in appearance but slightly thinner than the standard data connector.
Additional pins Some SATA drives, in particular mechanical ones, come with an extra 4 or more jumper pin interface which isn't uniformly standardized but nevertheless serves similar purpose defined by each drive manufacturer. As IDE drives used those extra pins for setting up Master and Slave drives, on SATA drives, those pins are generally used to select different Power modes for use in USB-SATA bridges or enables additional features like Spread Spectrum Clocking, SATA Speed Limit or Factory Mode for Diagnostics and Recovery, by the use of a jumper.
eSATA ports Standardized in 2004, eSATA (
e standing for external) provides a variant of SATA meant for external connectivity. It uses a more robust connector, longer shielded cables, and stricter (but backward-compatible) electrical standards. The protocol and logical signaling (link/transport layers and above) are identical to internal SATA. The differences are: • Minimum transmit amplitude increased: Range is 500–600 mV instead of 400–600 mV. • Minimum receive amplitude decreased: Range is 240–600 mV instead of 325–600 mV. • Maximum cable length increased to from . • The eSATA cable and connector is similar to the SATA 1.0a cable and connector, with these exceptions: • The eSATA connector is mechanically different to prevent unshielded internal cables from being used externally. The eSATA connector discards the L-shaped key and changes the position and size of the guides. • The eSATA insertion depth is deeper: 6.6 mm instead of 5 mm. The contact positions are also changed. • The eSATA cable has an extra shield to reduce
EMI to FCC and CE requirements. Internal cables do not need the extra shield to satisfy EMI requirements because they are inside a shielded case. • The eSATA connector uses metal springs for shield contact and mechanical retention. • The eSATA connector has a design-life of 5,000 matings; the ordinary SATA connector is only specified for 50. Aimed at the consumer market, eSATA enters an external storage market served also by the USB and FireWire interfaces. The SATA interface has certain advantages. Most external hard-disk-drive cases with FireWire or USB interfaces use either PATA or SATA drives and "bridges" to translate between the drives' interfaces and the enclosures' external ports; this bridging incurs some inefficiency. Some single disks can transfer 157 MB/s during real use, or FireWire or USB+FireWire bridges; eSATA does not suffer from these issues provided that the controller manufacturer (and its drivers) presents eSATA drives as ATA devices, rather than as
SCSI devices, as has been common with
Silicon Image,
JMicron, and
Nvidia nForce drivers for Windows Vista. In those cases SATA drives do not have low-level features accessible. The eSATA version of SATA 6G operates at 6.0 Gbit/s (the term "SATA III" is avoided by the
SATA-IO organization to prevent confusion with SATA II 3.0 Gbit/s, which was colloquially referred to as "SATA 3G" [bit/s] or "SATA 300" [MB/s] since the 1.5 Gbit/s SATA I and 1.5 Gbit/s SATA II were referred to as both "SATA 1.5G" [bit/s] or "SATA 150" [MB/s]). Therefore, eSATA connections operate with negligible differences between them. Once an interface can transfer data as fast as a drive can handle them, increasing the interface speed does not improve data transfer. There are some disadvantages, however, to the eSATA interface: • Devices built before the eSATA interface became popular lack external SATA connectors. • For small form-factor devices (such as external 2.5-inch disks), a PC-hosted USB or FireWire link can usually supply sufficient power to operate the device. However, eSATA connectors cannot supply power, and require a power supply for the external device. The related
eSATAp (but mechanically incompatible, sometimes called
eSATA/USB) connector adds power to an external SATA connection, so that an additional power supply is not needed. few new computers have dedicated external SATA (eSATA) connectors, with USB3 dominating and USB3 Type C, often with the
Thunderbolt alternate mode, starting to replace the earlier USB connectors. Still sometimes present are single ports supporting both USB3 and eSATA. Desktop computers without a built-in eSATA interface can install an eSATA
host bus adapter (HBA); if the motherboard supports SATA, an externally available eSATA connector can be added. Notebook computers with the now rare
Cardbus or
ExpressCard could add an eSATA HBA. With passive adapters, the maximum cable length is reduced to due to the absence of compliant eSATA signal-levels.
eSATAp port eSATAp stands for powered eSATA. It is also known as Power over eSATA, Power eSATA, eSATA/USB Combo, or eSATA USB Hybrid Port (EUHP). An eSATAp port combines the four pins of the USB 2.0 (or earlier) port, the seven pins of the eSATA port, and optionally two 12 V power pins. Both SATA traffic and device power are integrated in a single cable, as is the case with USB but not eSATA. The 5 V power is provided through two USB pins, while the 12 V power may optionally be provided. Typically desktop, but not notebook, computers provide 12 V power, so can power devices requiring this voltage, typically 3.5-inch disk and CD/DVD drives, in addition to 5 V devices such as 2.5-inch drives. Both USB and eSATA devices can be used with an eSATAp port, when plugged in with a USB or eSATA cable, respectively. An eSATA device cannot be powered via an eSATAp cable, but a special cable can make both SATA or eSATA and power connectors available from an eSATAp port. An eSATAp connector can be built into a computer with internal SATA and USB, by fitting a bracket with connections for internal SATA, USB, and power connectors and an externally accessible eSATAp port. Though eSATAp connectors have been built into several devices, manufacturers do not refer to an official standard.
Pre-standard implementations • Prior to the final eSATA 6 Gbit/s specification many add-on cards and some motherboards advertised eSATA 6 Gbit/s support because they had 6 Gbit/s SATA 3.0 controllers for internal-only solutions. Those implementations are non-standard, and eSATA 6 Gbit/s requirements were ratified in the July 18, 2011 SATA 3.1 specification. Some products might not be fully eSATA 6 Gbit/s compliant.
Mini-SATA (mSATA) Mini-SATA (abbreviated as mSATA), which is distinct from the micro connector, Applications include
netbooks,
laptops and other devices that require a
solid-state drive in a small footprint. The physical dimensions of the mSATA connector are identical to those of the
PCI Express Mini Card interface, but the interfaces are electrically incompatible; the data signals (TX±/RX± SATA, PETn0 PETp0 PERn0 PERp0 PCI Express) need a connection to the SATA host controller instead of the
PCI Express host controller. The
M.2 specification has superseded both mSATA and PCI Express Mini.
SFF-8784 connector Slim 2.5-inch SATA devices, in height, use the twenty-pin
SFF-8784 edge connector to save space. By combining the data signals and power lines into a slim connector that effectively enables direct connection to the device's
printed circuit board (PCB) without additional space-consuming connectors, SFF-8784 allows further internal layout compaction for portable devices such as
ultrabooks. Pins 1 to 10 are on the connector's bottom side, while pins 11 to 20 are on the top side. is an interface that supports either SATA or
PCI Express storage devices. The host connector is backward compatible with the standard 3.5-inch SATA data connector, allowing up to two legacy SATA devices to connect. At the same time, the host connector provides up to two
PCI Express 3.0 lanes as a pure PCI Express connection to the storage device, allowing bandwidths of up to 2 GB/s. Instead of the otherwise usual approach of doubling the native speed of the SATA interface, PCI Express was selected for achieving data transfer speeds greater than 6 Gbit/s. It was concluded that doubling the native SATA speed would take too much time, too many changes would be required to the SATA standard, and would result in a much greater power consumption when compared to the existing PCI Express bus. In addition to supporting legacy
Advanced Host Controller Interface (AHCI), SATA Express also makes it possible for
NVM Express (NVMe) to be used as the logical device interface for connected PCI Express storage devices. As M.2 form factor, described below, achieved much larger popularity, SATA Express is considered as a failed standard and dedicated ports quickly disappeared from motherboards.
M.2 (NGFF) (2242) solid-state-drive (
SSD) connected into
USB 3.0 adapter and connected to computer
M.2, formerly known as the
Next Generation Form Factor (NGFF), is a specification for computer
expansion cards and associated connectors. It replaces the mSATA standard, which uses the PCI Express Mini Card physical layout. Having a smaller and more flexible physical specification, together with more advanced features, the M.2 is more suitable for
solid-state storage applications in general, especially when used in small devices such as ultrabooks or tablets. A M.2 SSD is "
keyed" to prevent insertion of a card connector (male) to an incompatible socket (female) on the host. Typically, M.2 SSDs with a
B key or
B+M key are SATA, while M.2 SSDs with
M key only are mostly
NVMe only and incompatible with SATA. The M.2 standard is designed as a revision and improvement to the mSATA standard, so that larger
printed circuit boards (PCBs) can be manufactured. While mSATA took advantage of the existing PCI Express Mini Card form factor and connector, M.2 has been designed to maximize usage of the card space, while minimizing the footprint. Supported host controller interfaces and internally provided ports are a superset to those defined by the SATA Express interface. Essentially, the M.2 standard is a small form factor implementation of the SATA Express interface, with the addition of an internal
USB 3.0 port. == Topology ==