SATA Cables – A Complete Guide

Serial Advanced Technology Attachment (SATA) or Serial ATA cables are used to connect devices in computer cable assemblies, such as storage devices, for example.

The SATA technology itself is a connecter interface primarily used for computer bus connections in storage applications. In this application, the cables are used to connect a mass storage device (e.g. hard disk drives, optical drives, solid-state memory drives) to a host bus adapter such as a motherboard.

SATA cables can connect a range of devices, including:

• Hard drives
• Optical drives
• Solid-state memory drives

Hot plugging is also possible with supported SATA cables. This process involves adding or removing devices in a computer setup while the system is running. The hot plugging functionality is also useful because it means that operating systems can automatically recognise devices added without needing to perform a full restart.

First introduced in 2001, SATA cables offer a faster data transfer than their predecessor. Please see below for more information on the data transfer rate for the different SATA interfaces:

SATA Interface	Interface Gb/s	Bandwidth Throughput
SATA I	1.5Gb/s	150MB/s
SATA II	3Gb/s	300MB/s
SATA III	6Gb/s	600MB/s

Conversely, Parallel Advanced Technology Attachment (PATA) cables are older and slower, meaning that they are rarely used nowadays.

On the other hand, if you are using a SATA cable to add additional storage to a configuration, you do not need to address the existing hard drive. Instead, you will need to follow these steps:

• Insert the new hard drive into an empty bay in the PC case, ideally with space between the new and existing drives to enable better airflow
• Ensure that the SATA cable connection ports are easily accessible then secure the drive in position
• Connect the SATA cable to the port on the hard drive, then connect the other end of the cable to the motherboard, taking care not to disturb or impede the connection to the existing HDD
• The primary drive should be connected to the motherboard’s lowest SATA port – usually SATA 0 or SATA 1
• Complete the process by ensuring all connections are secure, closing the PC casing, then powering the system up once it is safe to do so
• It may be necessary to format the new drive or potentially reinstall the operating system, depending on the specifics of your application

Understanding how to install a SATA cable for data connection to a motherboard is a little different. These cables feature a latch to prevent accidental disconnection. They also require a low insertion force for connection.

There are various different SATA cable types, ranging from varying lengths and connector types to products produced by differing brands. The best SATA cable will ultimately depend on your setup and individual requirements, so it is important to know what is available before you buy SATA cable.

There are two principle SATA cable connector types – power and data. The simplest way to identify the difference between the two types is that data is the smaller of the two (typically 7-pin) whereas power is larger (typically 15-pin).

Mini or micro SATA cables are also available for internal drives and assemblies involving small-form components. A final alternative is the e-SATA cable, which is best suited to outwardly connecting computers or laptops to external peripheral SATA devices such as hard drives.

This table provides a handy explanation of the principal types of SATA cables:

Type of SATA Cable	Definition	Uses and Applications
e-SATA	Cable available in lengths ranging from 0.5-2m	External connection to PCs
Low Profile SATA	Ultra-thin SATA cables with low profile connectors	Graphics cards
Micro SATA	SATA data cable	Internal drives and backplane applications
SATA Bracket	Dual-port e-SATA expansion brackets	Compatibility between computer outputs and e-SATA drives
SATA Bridge	SATA interface acting as a bridge between devices	Connecting ATA devices to SATA motherboards or PCI cards
SATA Power	SATA interface power cable	Connecting power adapters, extensions and splitters for SATA power and data cables
SATA-SATA	Standard SATA cables available in a variety of lengths	Standard SATA applications

SATA Power Cable Connectors

SATA power cable connectors are the larger of the two, featuring 15-pins. Three pins within the connector work in parallel to supply different voltages (3.3V, 5V, and 12V). Some early versions also offer the dated four-pin Molex connector (the standard used with PATA cables) but most modern SATA power cables simply offer the newer 15-pin connector. The benefits of SATA power cables include increased current capacity and reduced electrical impedance.

SATA Data Cable Connectors

As previously mentioned, SATA data connectors typically feature seven pins – explained in the chart below. In a standard assembly, one end of the cable will be connected to the hard drive, while the other will be connected to the motherboard. SATA data cables are typically small and compact, providing additional space for cooling the system. These data connectors also include differential signalling to reduce the risk of data loss during transfer.

SATA Pinout

The SATA interface has seven pins for data interface. This pinout displays the details for a standard SATA cable:

Pin	Name	Function
1	GND	Ground
2	A+	Transmit+
3	A-	Transmit-
4	GND	Ground
5	B-	Receive-
6	B+	Receive+
7	GND	Ground

SATA to USB Power Cables

SATA cables are ideal for using alongside SSD drives or assisting with laptop data transfer. Utilising increasingly commonplace USB technology, SATA to USB cables are designed to seamlessly work with a variety of PCs, laptops and devices to enable quick and easy usage capabilities. SATA to USB adaptors are also available.

SATA Power Cables

When it comes to SATA power cables, 15-pole, power and data all have the same pitch of connector pins, but each has a different number of ways.

It is also worth noting that adaptors are generally available for PC power supplies that feature alternative types of power connectors.

SATA Cables for HDDs

In a PC setup, SATA cables can be used to connect the hard disk to the motherboard. Hard disks typically feature multiple inlet ports, at least one of which will be SATA compatible. The SATA cable is also responsible for supplying power to the hard disk so additional hard drive power cables may not be required.

SATA cables are beneficial as their shape has been specifically designed to help maximise airflow inside a CPU, saving space and boosting performance.

It is also worth noting that SATA cables can be used to connect external hard drives to a PC via the e-SATA input. Likewise, it may be possible to connect an external hard drive to a computer using a SATA to USB adapter if the particular hard drive supports USB input.

SATA Cables for Laptops

If you are using a laptop rather than a standard PC, the chances are that the laptop’s storage devices (HDDs, SSDs etc) are attached directly to the motherboard. As a result, a SATA cable should not be necessary. The motherboard and the breakout boards connected to the storage devices are joined with a thin, flat SATA cable specially designed for use in laptop assemblies.

Can a SATA Cable Affect Speed?

Different types of SATA cable offer different speeds, as detailed below:

• SATA 1: 1.5Gbps
• SATA 2: 3.0Gbps
• SATA 3: 6.0Gbps

However, it is also worth noting that they are all backwards compatible.

Are SATA Cables Still Used?

While modern laptops typically include in-built, purpose-made SATA cables and alternative, faster technologies like PCI Express have since become available, SATA cables are still very much used today. Almost all modern hard drives use the SATA interface and as a general rule, only a few legacy hard drives still use the older PATA interface.