A Complete Guide to SATA Cables

Serial Advanced Technology Attachment (SATA) or Serial ATA cables are used in computer cable assemblies to connect storage devices to a motherboard or host adapter. SATA is a connector interface commonly used for mass storage devices such as hard disk drives (HDDs), optical drives (ODDs), and solid-state memory drives (SDDs).

SATA cables can connect a range of devices, including:

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

SATA supports hot plugging, allowing devices to be connected or removed while the system is running without requiring a reboot. This ensures operating systems recognize new or removed devices automatically.

In a computer, SATA cables serve two essential functions: transferring data and delivering power. Together, they enable smooth communication and reliable electricity supply between the motherboard, the storage devices (HDDs, SSDs), and optical drives (ODDs). The data cable handles high-speed data movement, while the power cable ensures devices receive the voltages needed to operate correctly.

SATA Data Cable Function

The function of a SATA data cable is to connect a storage device like HDD/SSD or ODD directly to the motherboard. It uses a 7-pin connector and supports differential signaling to reduce interference and improve signal integrity. In its current standard, SATA III, the data cable can transfer data at speeds up to 6 Gbps (gigabits per second).

This high bandwidth allows operating systems, applications, and large files to be read from and written to storage swiftly, which is vital for boot-times, file transfers, loading games, etc.

SATA Power Cable Function

The SATA power cable’s function is to supply electrical energy from the power supply unit (PSU) to the storage or optical drive. It uses a 15-pin connector that provides multiple voltage rails: +3.3V, +5V, and +12V.

These different voltages cover various parts inside the device, logic circuits usually need +5V (or sometimes +3.3V), motors or mechanical components often need +12V. Without reliable power delivery, the drives can behave erratically or fail to spin up.

Introduced in 2001, SATA cables replaced older Parallel ATA (PATA) cables, offering much faster data transfer rates:

PATA uses a wider 40-pin or 80-wire ribbon cable and is now rarely used due to lower speeds and bulkiness.

SATA cables vary by length, connector types, and form factor. Knowing the options available helps in choosing the best cable for each setup.

The two main connector types are:

• SATA Data Cable: Smaller 7-pin connector
• SATA Power Cable: Larger 15-pin connector

Special variants include:

• Mini or micro SATA: For small internal drives, such as 1.8" SSDs
• e-SATA: External SATA cables designed for connecting external drives to computers
• SATA to USB: Adapters to connect SATA drives externally via USB

Common SATA Cables

SATA Cables by Generation

SATA cables are categorized into generations, SATA I, II, and III, each offering different data transfer speeds. These generations are backward-compatible, meaning newer cables and devices can function with older ones, though at the older generation's maximum speed. For instance, a SATA III cable can work with a SATA I device, but the data transfer rate will be limited to 1.5 Gbps.

This backward compatibility ensures flexibility when upgrading components, allowing users to mix and match devices and cables across generations without compatibility issues.

SATA cable length is generally quite short as these cables are used internally inside PC cases. The maximum length tends to be around one meter. Larger SATA cables are available but these are rarely used because the extra cable length is just not necessary in standard assemblies.

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 earlier 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:

SATA to USB Power Cables

Designed for external data transfer or backup, SATA to USB cables enable connecting internal drives to external USB ports on laptops or desktops. SATA to USB adapters are popular for adding portable storage.

SATA Connectors

A SATA connector is the physical interface where a SATA cable plugs into a device. Connectors come in “male” and “female” forms to ensure devices mate correctly.

The male connector refers to the plug end on the SATA cable, it has protruding contacts and fits into a port. The female connector is the port (on storage devices like HDDs/SSDs or on the motherboard) with recessed sockets that accept the male plug.

This male/female distinction ensures proper orientation, preventing incorrect insertion, loose connections, or damage. Secure fit-ment via these connectors keeps data signals stable and hardware safe.

What SATA Cables Are Used For?

SATA Power Cables

SATA power cables have 15 pins (power and ground) with multiple ways to supply voltage. Adapters exist for converting older PSU connectors to SATA power.

SATA Cables for HDDs

In a PC setup, SATA cables connect internal hard drives to motherboards. 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 maximize 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.