SATA HD stands for Serial Advanced Technology Attachment Hard Disk. It is a type of hard disk drive that uses the Serial ATA interface to connect to a computer’s motherboard. SATA was designed to replace the older Parallel ATA (PATA) standard and has become the most common interface for connecting hard drives in desktop and laptop computers.
What is SATA?
SATA stands for Serial Advanced Technology Attachment. It is an interface used to connect storage devices like hard disk drives and solid state drives to a computer’s motherboard. The SATA interface transmits data in a serial fashion one bit at a time, rather than in parallel like its predecessor PATA. The serial design allows SATA to operate at much higher speeds compared to PATA.
Some key advantages of SATA over PATA include:
- Higher transfer speeds – SATA has much higher maximum bandwidth than PATA, starting at 150 MB/s for the original SATA 1.0 specification, up to 600 MB/s for the latest SATA 3.0 specification.
- Thinner cables – SATA cables are much thinner and more flexible than PATA ribbons cables, allowing improved air flow and less clutter inside the computer case.
- Native hot swapping – SATA supports hot swapping so drives can be removed and added while the computer is running. PATA does not allow this.
- Simpler cabling – SATA data and power are transmitted over a single cable. PATA requires two cables per drive.
The SATA interface is the de facto standard for connecting HDDs, SSDs and optical drives in modern PCs. Almost all new motherboards provide multiple SATA ports to support adding high performance storage devices.
SATA Hard Disk Drives
A SATA HDD is simply a hard disk drive that uses the SATA interface to connect to the motherboard instead of the older PATA standard. Most consumer hard drives produced since around 2003 have adopted the SATA interface.
There have been several revisions of the SATA specification over the years, each increasing the maximum bandwidth:
- SATA 1.0 – First introduced in 2003, supports up to 150MB/s bandwidth.
- SATA 2.0 – Released in 2004, up to 300MB/s transfer speeds.
- SATA 3.0 – Introduced in 2009, provides up to 600MB/s.
- SATA 3.1 – Minor revision in 2011, added support for mSATA.
- SATA 3.2 – Released in 2013, supports up to 16Gb/s transfer speeds.
- SATA 3.3 – Minor update in 2016, added new power management and cryptography features.
- SATA 3.4 – Latest spec from 2017, includes interface power management improvements.
In addition to increasing interface speed, newer SATA revisions have added support for features like hot plugging, NCQ (native command queuing for increased performance), TRIM support, and more. The latest 3.4 spec also optionally supports the new NVM Express protocol to better support SSDs.
Advantages of SATA HDs
Here are some of the major advantages of SATA hard drives compared to the older PATA drives:
- Faster interface – SATA provides much higher maximum bandwidth than PATA, starting at 1.5Gbps for SATA 1.0 up to 16Gbps for the latest SATA 3.2 specification.
- Thinner cables – The thin SATA cables allow for better airflow and reduced clutter in computer cases compared to bulky PATA ribbon cables.
- Hot swapping – SATA natively supports hot swapping so drives can be replaced or added without powering down the system.
- Simpler cabling – SATA uses a single cable for data and power. PATA requires two separate connectors per drive.
- Native command queuing – NCQ optimizes read/write head movements to increase performance.
- TRIM support – TRIM improves performance with SSDs by clearing invalid data blocks.
- Power management – SATA has built-in support for power saving modes to reduce energy use.
Overall, the SATA interface provides substantial improvements over the older PATA standard. The introduction of SATA corresponded with other advances in hard drive technology in the early 2000s like increased spindle speeds and areal density. These factors combined to usher in a new generation of much higher performance hard drives.
Types of SATA Cables and Connectors
There are a few different types of SATA cables and connectors used to hook up SATA hard drives:
- SATA Data Cable – Transmits the SATA data signals. Typically has a small L-shaped connector on each end.
- SATA Power Cable – Provides power to the drive. Usually has a 15-pin connector on one end and a L-shaped plug on the other.
- SATA Combination Cable – Combines both data and power in one cable for simplicity. Has L-shaped SATA connectors on both ends.
The SATA data and power cables are typically separate. However, combination cables that integrate both power and data into one cable are also available. These can help reduce cable clutter and simplify connections in some cases.
There are three main SATA connector types:
- SATA 15-Pin Power – Typically used on power supplies and hard drive enclosures to deliver 12V and 5V power.
- SATA 7-Pin Data – Found on SATA data cables to transmit data signals. Often L-shaped for easier connections.
- SATA 7+15 Pin Combo – Combines the 15-pin power and 7-pin data connectors into one larger L-shaped plug. Used on combination SATA cables.
The small, L-shaped SATA connectors take up much less space than the wide, flat PATA ribbon cable connectors, allowing SATA ports to be stacked closer together on motherboards and drive enclosures.
SATA HD Speeds
SATA hard disk drives are mechanical devices that consist of spinning platters and moveable read/write heads. Because of this, their performance is primarily limited by the mechanical and physical factors of the drive rather than the SATA interface speed.
Some typical SATA hard drive speeds:
- 5400 RPM – Lower performance, ranges from 50-100 MB/s sustained transfer rates.
- 7200 RPM – Faster, around 100-150 MB/s sustained transfers.
- 10,000 RPM – High performance, 140-200+ MB/s transfer speeds.
- 15,000 RPM – Top-end enterprise class performance, 200+ MB/s.
HDD speeds are primarily influenced by the rotational speed of the platters measured in RPMs. Faster RPMs allow the drive heads to access data quicker. beyond RPMs, factors like cache size, platter density, and seek times also impact overall speed.
While SATA interface speeds go up to 16Gbps, hard drives cannot saturate those links. But the faster SATA revisions still benefit HDDs by reducing protocol overhead and bottlenecks.
SATA HDD Capacities
SATA hard drives are available in a wide range of storage capacities from small portables drives up to massive enterprise class models.
Some typical SATA hard disk drive capacities:
- 1-2 TB – Typical for basic desktop PC internal drives.
- 3-4 TB – Common for home NAS and external storage drives.
- 6-8 TB – Used in high-capacity external and NAS hard drives.
- 10-14 TB – Found in enterprise-class 3.5″ hard drives.
- 16-18 TB – Largest conventional HDD capacities available today.
Advances in areal density by drive manufacturers have rapidly grown SATA hard drive capacities over the years. While the largest 10,000+ RPM enterprise drives may be limited to around 1-2 TB, slower 5400 RPM drives are available up to 18TB for NAS and backup applications.
SATA Hard Drive Form Factors
SATA hard disk drives come in a variety of physical sizes known as form factors. The most common SATA HDD form factors are:
- 3.5-inch – The largest mainstream form factor used for desktop PCs and NAS enclosures. Offers the highest capacities.
- 2.5-inch – Smaller drives used mainly in laptops. Also found in game consoles and external enclosures.
- 1.8-inch – Very small hard drives for compact portable devices and embedded systems.
- mSATA / M.2 SATA – SSD form factors that also support rotational SATA hard drives.
3.5″ drives are the workhorses used in desktop PCs and servers where large capacities are required. 2.5″ drives balance smaller size and moderate capacities for mobile and portable applications.
SATA HDD vs SSD
The SATA interface is used to connect both traditional hard disk drives (HDD) as well as newer solid state drives (SSD). Here is a brief comparison between SATA HDDs vs SATA SSDs.
| Attribute | SATA HDD | SATA SSD |
|---|---|---|
| Storage medium | Magnetic platters | NAND flash memory chips |
| Speed | Up to 210 MB/s (15K RPM) | Up to 550 MB/s (SATA 3.0) |
| Max capacity | Up to 18 TB | Typically up to 8 TB |
| Latency | Average 10-15 ms | Very low, under 0.1 ms |
| Power usage | 7-15 watts typical | 2-7 watts typical |
| Shock resistance | Moderate, platters can crash | Very high, no moving parts |
| Endurance | Virtually unlimited writes | Limited write cycles before wear |
| Price (per GB) | $0.02 – $0.05 | $0.10 – $0.30 |
In summary:
- HDDs have lower costs per GB of storage compared to SSDs.
- SSDs are much faster, more power efficient, and more durable due to having no moving parts.
- HDDs can offer far larger maximum capacities compared to SSDs.
Both technologies have their place and are often combined together in systems with SSDs for the OS and apps, and large SATA HDDs providing mass storage capacity for data.
Conclusion
SATA hard disk drives have been the dominant hard drive technology for over 15 years. The SATA interface offers major advantages over the older PATA standard including much faster speeds, thinner cables, hot-swapping support, simpler cabling and more.
While solid state drives are taking over many traditional HDD application areas like laptop storage, SATA HDDs continue to offer a compelling value proposition for bulk data storage thanks to very low costs per gigabyte and drive capacities up to 18TB.
With steady advances in areal density allowing drive capacities to keep growing while costs decline, SATA hard disk drives will remain an essential storage technology for the foreseeable future.