SATA | Technical Characteristics | instrumentic.info

The logo SATA
The logo SATA

SATA

The SATA standard (Serial Advanced Technology Attachment) , connects devices such as hard drives. It specifies a transfer format and a wiring format.

The first SATA models appeared in 2003.

The SATA I (1.x revision) interface, known as SATA 1.5Gbps, is the first generation of SATA interface clocked at 1.5Gbps. The bandwidth that is supported by the interface can reach 150MB/s.

The SATA II interface (2.x revision), known as SATA 3Gb/s, is a second generation of interface clocked at 3.0 Gb/s. The bandwidth that is supported by the interface can reach 300MB/s.

The SATA III interface (3.x revision) that appeared in 2009, known as SATA 6Gb/s, is a third generation SATA interface clocked at 6.0Gb/s. The bandwidth that is supported by the interface can reach 600MB/s. This interface is retrocompatible with the SATA II 3 Gb/s interface.

The SATA II features offer retrocompatibility to operate on SATA I ports.
The SATA III features provide retrocompatibility to operate on SATA I and II ports.
However, the speed of the disk will be slower due to the speed limitations of the port.

The connector SATA
The connector SATA

SATA connectors

The data is transmitted by 2 pairs of cables (one pair for transmission and one for reception), protected by 3 mass cables.
These seven conductors are grouped on a flat, inflexible tablecloth with 8mm connectors at each end. The length can be up to 1 meter.
The airflow, and therefore the cooling, is improved by this small width.

As an indication

Pin No. Function
1 GRD
2 A+ (transmission)
3 A− (transmission)
4 GRD
5 B− (reception)
6 B+ (reception)
7 GRD

The SATA has only one cable device (point-to-point connection). Connectors have deceives, so it is not possible to turn them upside down. Some cables have locking, others don't. The absence of a lock can cause unannounced disconnection if handled.
The same physical connectors are used for 3.5- and 2.5-inch hard drives as well as for internal CD/DVD players/engravers.

SATA uses 8b/10b coding to make transfers, allowing you to work on better frequencies. This coding ensures a good recovery of the clock signal in very high-speed reception and balances the number of 0 and 1 to avoid the presence of a continuous current on the line.

The SATA power connector has 15 pins
The SATA power connector has 15 pins

Power connector

Native SATA hard drives require a power-electric connector that is part of the standard. The power connector is similar to the data connector, but wider.
It requires 15 pins to provide three power voltages if necessary : 3.3V - 5V and 12V.




Pin No. \tFunction
1 \t 3,3 V
2 3,3 V
3 3,3 V
4 \t GRD
5 GRD
6 GRD
7 \t 5 V
8 5 V
9 5 V
10 \t\t GRD
11 \t\t Activity
12 \t\t GRD
13 \t 12 V
14 12 V
15 12 V

Other types of SATA

Mini-SATA is an adaptation of the SATA protocol for Netbooks
Mini-SATA is an adaptation of the SATA protocol for Netbooks

The mini-SATA

It is an adaptation of the SATA protocol for laptops, but also for devices using SSDs.
The mini-SATA connector is smaller than the SATA but offers the same performance. The mini-SATA looks a lot like a mini PCI-Express card, it supports the SATA III standard at 6 Gbps.

External SATA is an adaptation of the SATA protocol for connecting external devices
External SATA is an adaptation of the SATA protocol for connecting external devices

The eSATA

External-SATA is an adaptation of the SATA protocol for connecting external devices. Its main features are :

- Emission voltage above SATA (500-600 mV instead of 400-600 mV)
- Reception voltage below SATA (240-600 mV instead of 325-600 mV)
- Identical protocol, so that you can use the same equipment
- Maximum cable length above SATA (2 m instead of 1 m)


Several manufacturers offer Combo sockets in which the eSATA port shares the USB2 or USB3 socket for space reasons. Since USB 3.0, the eSATA port is competitive because USB offers comparable speeds and better ergonomics. eSATA can reach about 750 MB/s, and USB 3,600 MB/s.

Transfer speeds for all types of external connections in ascending order :

USB 1.1 1,5 Mo / s
Firefire 400 50 Mo / s
USB 2.0 60 Mo / s
FireWire 800 100 Mo / s
FireWire 1200 150 Mo / s
FireWire 1600 200 Mo / s
FireWire 3200 400 Mo / s
USB 3.0 600 Mo / s
eSATA 750 Mo / s
USB 3.1 1,2 Go / s
Thunderbolt 1,2 Go / s × 2 (2 channels)
USB 3.2 2,5 Go / s
Thunderbolt 2 2,5 Go / s
USB 4.0 5 Go / s
Thunderbolt 3 5 Go / s
Thunderbolt 4 5 Go / s (unchanged)

The micro SATA is an interface especially aimed at ultraportable PC
The micro SATA is an interface especially aimed at ultraportable PC

The micro SATA

The micro-SATA interface is available for 1.8\ hard drives, and is mainly aimed at ultraportable PCs and tablets.

The micro-SATA connector looks like the standard SATA connector in smaller, the power connector is more compact (9 pins instead of 15), it does not offer the voltage of 12 V and is limited to the 3.3 V and 5 V, moreover it has a deception located between the pins 7 and 8.

The theoretical transfer rates are 230 Mbps in reading and 180 MB/s in writing.