Serial ATA SATA

Serial ATA (SATA)

Year created	2003
Supersedes	Parallel ATA (PATA)
Speed	1.5, 3.0, 6.0 and 16 Gbit/s
Style	Serial
Hotplugging interface	Yes[1]
External interface	Optional (eSATA)

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Serial ATA (SATA, abbreviated from Serial AT Attachment^[2]) is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives and optical drives


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SATA data connector pinout^[31]

Pin #		Mating	Function
	1	1st	Ground
	2	2nd	A+ (Transmit)
	3	2nd	A− (Transmit)
	4	1st	Ground
	5	2nd	B− (Receive)
	6	2nd	B+ (Receive)
	7	1st	Ground
—			Coding notch

The SATA standard defines a data cable with seven conductors (3 grounds and 4 active data lines in two pairs) and 8 mm wide wafer connectors on each end. SATA cables can have lengths up to 1 metre (3.3 ft), 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 45 centimetres (18 in) in length by the PATA specification; however, cables up to 90 centimetres (35 in) are readily available. Thus, SATA connectors and cables are easier to fit in closed spaces, and reduce obstructions to air cooling. They are more susceptible to accidental unplugging and breakage than PATA, but cables can be purchased that have a locking feature, whereby a small (usually metal) spring holds the plug in the socket.
SATA connectors may be straight, right-angled, or left angled. Angled connectors allow lower profile connections. Right-angled (also called 90 degree) connectors lead the cable immediately away from the drive, on the circuit board side. Left-angled (also called 270 degree) connectors lead the cable across the drive towards its top.


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SATA connector on a 3.5-inch hard drive, 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

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Pin #		Mating	Function
—			Coding notch
	1	3rd	3.3 V
	2	3rd
	3	2nd
	4	1st	Ground
	5	2nd
	6	2nd
	7	2nd	5 V
	8	3rd
	9	3rd
	10	2nd	Ground
	11	3rd	Staggered spinup/activity (in supporting drives)
	12	1st	Ground
	13	2nd	12 V
	14	3rd
	15	3rd

A 15-pin SATA power connector; this particular connector is missing the 3.3 V (orange) wire.

SATA specifies a different power connector than the decades-old four-pin Molex connector used on Parallel ATA (PATA) devices. It is a wafer-type connector, like the SATA data connector, but much wider (15 pins versus seven) to avoid confusion between the two. Some early SATA drives included the old 4-pin Molex power connector together with the new 15-pin connector, but most SATA drives now have only the latter.
The new SATA power connector contains many more pins for several reasons:^[32]

• 3.3 V is supplied along with the traditional 5 V and 12 V supplies. However, very few drives actually use it, so they may be powered from an old 4-pin Molex connector with an adapter.
• To reduce impedance and increase current capability, each voltage is supplied by three pins in parallel, though one pin in each group is intended for precharging (see below). Each pin should be able to carry 1.5 A.
• Five parallel pins provide a low-impedance ground connection.
• Two ground pins, and one pin for each supplied voltage, support hot-plug precharging. Ground pins 4 and 12 in a hot-swap cable are the longest, so

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Pin #		Mating	Function
	1	3rd	3.3 V
	2	2nd
	3	1st	Ground
	4	1st
	5	2nd	5 V
	6	3rd
	7	3rd	Reserved
—			Coding notch
	8	3rd	Vendor specific
	9	2nd

A 1.8" (46 mm) micro SATA hard drive with numbered data and power pins on the connector.

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connector.
The micro connector originated with SATA 2.6. It is intended for 1.8-inch (46 mm) hard drives. There is also a micro data connector, similar in appearance to but slightly thinner than the standard data connector.
The micro SATA connector is sometimes called uSATA or μSATA

eSATA

The official eSATA logo

SATA (left) and eSATA (right) connectors

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.

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SFF-8784 pin assignments^[46]

Bottom side				Top side
Pin	Function	Pin	Function	Pin	Function	Pin	Function
1	Ground	6	Unused	11	Ground	16	+5 V
2	Ground	7	+5 V	12	B+ (Transmit)	17	Ground
3	Ground	8	Unused	13	B− (Transmit)	18	A− (Receive)
4	Ground[b]	9	Unused	14	Ground	19	A+ (Receive)
5	LED	10	Ground	15	+5 V	20	Ground

Slim 2.5-inch SATA devices, 5 mm (0.20 inches) in height, use the 20-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.^[46]
Pins 1 to 10 are on the connector's bottom side, while pins 11 to 20 are on the top side.^[46]
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Comparison with other buses[edit]

See also: List of device bit rates

Name	Raw bandwidth	Transfer speed	Max. cable length	Power provided	Devices per channel
eSATA	6 Gbit/s	600 MB/s	2 m with eSATA HBA (1 m with a passive adapter)	No	One (15 with a port multiplier)
eSATAp	3 Gbit/s	300 MB/s	2 m with eSATA HBA (1 m with a passive adapter)	5 V/12 V[60]	One (15 with a port multiplier)
SATA revision 3.2	16 Gbit/s	1.97 GB/s[c]	1 m	No	One (15 with a port multiplier)
SATA revision 3.0	6 Gbit/s	600 MB/s[61]	1 m	No	One (15 with a port multiplier)
SATA revision 2.0	3 Gbit/s	300 MB/s	1 m	No	One (15 with a port multiplier)
SATA revision 1.0	1.5 Gbit/s	150 MB/s[62]	1 m	No	One per line
PATA (IDE) 133	1.064 Gbit/s	133.3 MB/s[d]	0.46 m (18 in)	5 V (44-pin for 2.5" drives only)	Two
SAS-3	12 Gbit/s	1.2 GB/s	10 m	No	1-8 (> 65k with expanders)
SAS-2	6 Gbit/s	600 MB/s	10 m	No	One (> 65k with expanders)
SAS 300	3 Gbit/s	300 MB/s	10 m	No	One (> 65k with expanders)
SAS 150	1.5 Gbit/s	150 MB/s	10 m	No	One (> 65k with expanders)
IEEE 1394 (FireWire) 3200	3.144 Gbit/s	393 MB/s	100 m (more with special cables)	15 W, 12–25 V	63 (with a hub)
IEEE 1394 (FireWire) 800	786 Mbit/s	98.25 MB/s	100 m[63]	15 W, 12–25 V	63 (with a hub)
IEEE 1394 (FireWire) 400	393 Mbit/s	49.13 MB/s	4.5 m[63][64]	15 W, 12–25 V	63 (with a hub)
USB 3.1	10 Gbit/s	1.21 GB/s[e]	3 m	100 W, 5, 12 or 20 V[65]	127 (with a hub)
USB 3.0[f]	5 Gbit/s	400 MB/s or more (protocol overhead, flow control, framing excluded)[66]	3 m[67]	4.5 W, 5 V	127 (with a hub)[67]
USB 2.0	480 Mbit/s	35 MB/s	5 m[68]	2.5 W, 5 V	127 (with a hub)[67]
USB 1.1	12 Mbit/s	1.5 MB/s	3 m	Yes	127 (with a hub)[67]
SCSI Ultra-320	2.56 Gbit/s	320 MB/s	12 m	No	15 (plus the Host Bus Adapter/Host)
10GFC Fibre Channel	10.52 Gbit/s	1.195 GB/s	2 m – 50 km	No	126 (16,777,216 with switches)
4GFC Fibre Channel	4.25 Gbit/s	398 MB/s	12 m	No	126 (16,777,216 with switches)
InfiniBand Quad Rate	10 Gbit/s	0.98 GB/s	5 m (copper)[69][70] <10 fiber="" km="" nbsp="" p="">	No	One with point-to-point, many with switched fabric
Thunderbolt	10 Gbit/s	1.22 GB/s	3 m (copper) 100 m (fiber)	10 W (copper only)	Seven
Thunderbolt 2	20 Gbit/s	2.44 GB/s	3 m (copper) 100 m (fiber)	10 W (copper only)	Seven

Unlike PATA, both SATA and eSATA support hot-swapping by design. However, this feature requires proper support at the host, device (drive), and operating-system levels. In general, all SATA devices (drives) support hot-swapping (due to the requirements on the device-side), also most SATA host adapters support this command


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https://en.wikipedia.org/wiki/Serial_ATA