Definitions of SATA

SATA

According to AbbreviationFinder.org, SATA or Serial Advanced Technology Attachment. Interface data transfer between the motherboard or Motherboard and various storage devices such as hard drives or optical devices as snimači CD or DVD. This interface replaces the traditional IDE interface or technically known as Parallel ATA or P-ATA Interface. SATA provides superior performance, higher speeds, better utilization of multiple drives, longer data transmission cable lengths, and the ability to instantly connect drives – that is, insert the device without having to shut down the computer or suffer a short circuit.

History

Since before the year 2000, the foundations and intentions of a group that tried to revolutionize, with new device interfaces, the interconnection of data storage devices with the motherboard were laid, improving transfer rates and increasing speeds and levels of communication. access. In the same year 2000, a group named Serial ATA Working Group was formed, investing and giving an extraordinary boost to the matter. The same group, now Serial II ATA Working Group, industrially associated with the Serial ATA II Steering Committee, laid the necessary foundations to establish itself in the market by becoming a standard. Later, in 2004, they changed the name to Serial ATA International Organization (SATA-IO).

Background

In November 2001, a group of hardware manufacturers, including Intel, Dell, Maxtor, APT Technologies, and Seagate, created the Seria ATA Working Group to address the needs of next-generation interfaces. Later, in 2004, they changed the name to Serial ATA International Organization (SATA-IO).

At this time, after the improvements of the ATA-7 specification with which transfers of 133 MB / s had been achieved, the traditional PATA interface model (“Parallel ATA”) began to show symptoms of exhaustion, after having provided efficient services since its initial conception in the mid-80s. The idea among specialists was that it was necessary to look in another direction. At the same time, fiber optic and wireless link technology had led to great advances in the field of serial communications. In this environment, efforts were directed toward a new serial architecture specification for the ATA interface.

As shown in Figure 1 and customary in computer designs, the new architecture, known as Serial ATA (SATA), adopts a layered structure. The command layer is a superset of the older ATA architecture; so that the new devices are compatible with traditional ATA protocols, and are therefore compatible with existing applications. However, the physical layer is different, which represents a breaking point in the sense that the new SATA devices are not compatible with the previous ones. However, the new architecture offers enough enhancements to justify the change.

The idea is that ATA devices of any type (serial or parallel) share a common set of orders, and organize the connection of these devices in a structure where there are specific addresses, domains and devices. An organization vaguely reminiscent of the Internet from which it is inspired (an ATA domain contains a SATA host controller and a device).

Speeds

The first generation, SATA I, established transfer values ​​of 150 MB / s per second. The second generation, SATA II, reached 300 MB / s, also known as Serial ATA-300 while the current SATA III achieves the speed of up to 600 MB / s. Units that support 3Gb / s speed are compatible with a 1.5 Gb / s bus.

The following table shows the actual speed calculation for SATAI 1.5 Gb / s and SATAII 3 Gb / s:

Frequency Bits / clock Actual speed
SATA I 1500 MHz 1 150 MB / s
SATA II 3000 MHz 1 300 MB / s
SATA III 6000MHz 1 600 MB / s

Identification of the Pins in the Connector

Pin ID Specification
Pin 1 GND Land
Pin 2 HT + / DR + Differential transmission +
Pin 3 HT- / DR- Differential transmission –
Pin 4 GND Land
Pin 5 HR- / DT- Differential reception –
Pin 6 HR- / DT + Differential reception +
Pin 7 GND Land

Physic structure

Each SATA or SAS (“Serial Attached SCSI”) port, multiplier, device, or adapter has a unique 64-bit port number. A kind of MAC or barcode of the product with: a 4-bit NAA code; a 24-bit manufacturer code assigned by the regulatory authority, and a device code available to each 36-bit manufacturer.

Topology

SATA is a “peer-to-peer” architecture. That is, the connection between port and device is direct, each device is directly connected to a SATA controller, thus, each device enjoys the full bandwidth, of the connection, without the overhead inherent in the arbitration mechanisms and collision detection as it happened in the old PATA that the interfaces were segmented into master and slave.

The host controller is embedded in the motherboard or installed as a card in one of its sockets, which acts as a bridge between the parallel data on the bus and the SATA device. There are controllers with more than one output (usually 4 or 8) so that several devices can be connected. Port multipliers have also been designed that allow increasing the number of connections on a controller port, in order to increase the number of connected devices.

In addition to the task of serializing / parallelizing the data, an important part of the work of the controller is related to the connection and disconnection protocols of the peripheral, which are quite sophisticated in this type of interface, since the capacity of hot plugging is foreseen.. The connection protocol is able to identify the type of device connected; detect if it works correctly; negotiate connection speed, etc. The Serial ATA interface has certain similarities with the USB interface, although SATA is much faster than that, and the devices are not powered by the bus itself.

Cables and Connectors on devices

The type of cabling used in the SATA interface is much thinner and more aerodynamic than the previous PATA, which allows these cables, being much thinner, to facilitate the flow of air inside the box, reducing the heating of the equipment.

Another advantage of this type of port is that it allows up to 1 meter of cable length compared to the length of less than half a meter in its ATA predecessor.

Regarding the power cable, it is also different from that of the original ATA disks, and the working voltages are lower, having a lower consumption. In addition, the traditional Master / Slave configuration is not necessary, since the SATA units are connected one per port, indicating in the Setup only which is the SATA to which the boot order should be directed first (Boot sequence).

Advantage

  • It has a data transfer speed of up to 1.5 Gigabits (150 MB / s 300 MB / s 600 MB / s real) and a higher bandwidth, apart from its architecture demonstrates a greater capacity for future performance increases in subsequent versions.
  • Data also travels in a more comprehensive and secure way, as well as faster.
  • The cables are more compact and in my opinion, more aesthetic, they can be longer (up to two meters in their first version). Its connector has also changed thus allowing Hotplug.
  • Finally, it is perfectly scalable with RAID and allows compatibility with all the software and drivers that operated with the previous PATA interfaces.

External SATA (eSATA)

eSATA: (E xternal S erial A dvanced T echnology A tachement) is an external version of SATA put into effect in 2004, through which it is possible to achieve SATA speeds in external devices, without having to lose characteristics of the disks in the exchange of protocols from PATA / SATA to USB / Firewire.

Of course, the length of the cable is reduced to 2 meters and the voltage changes slightly. This standard is compatible with RAID and a large number of motherboards are adapting to be able to use devices with this interface.

Advantages of this new system.

In terms of speed, there are great advantages, since the new interface starts working at 150MBytes / sec (133 maximum in ATA), currently the SATA2 type is usual, with a transfer rate of 300MBytes / sec.

Another great improvement over the previous system (in my opinion) is the type of wiring used, much thinner and more aerodynamic than the previous one, which allows these cables, being much thinner, to facilitate air flow. inside the box, reducing the heating of our equipment.

Another advantage of this type of port is that it allows up to 1 meter of cable length (less than half a meter for ATA connections).

Regarding the power cable, it is also different from that of the original ATA disks, and the working voltages are lower, having a lower consumption.

In addition, the traditional Master / Slave configuration is not necessary, since SATA units connect one per port, indicating in the Setup only which is the SATA to which the boot order should be directed first (Boot sequence).

SATA