ATA, short for Advanced Technology Attachment, refers to a standard interface used to connect storage devices like hard disk drives and solid state drives to a computer’s motherboard. ATA has a long history stretching back to the 1980s and has gone through several iterations over the decades.
Brief history of ATA
The first version of ATA, also known as IDE (Integrated Drive Electronics), was introduced in 1986 and provided a standard way to connect storage drives without requiring a separate controller card. This helped simplify computer hardware and made storage devices easier to install and use.
ATA/IDE went through several major revisions over the following decades:
- ATA-1 (1986): Initial standard supporting up to 2 hard drives
- ATA-2 (1988): Faster transfers and support for >2 hard drives
- ATA-3 (1997): SMART monitoring, faster modes
- ATA/ATAPI-4 (1998): Support for optical drives
- ATA/ATAPI-5 (2000): Higher speeds, new commands
- ATA/ATAPI-6 (2002): Native command queuing
- ATA/ATAPI-7 (2004): Serial ATA introduced
In 2003, the technology was renamed to PATA (Parallel ATA) to distinguish it from the new standard Serial ATA (SATA). PATA uses a parallel interface while SATA uses a serial interface.
The move from PATA to SATA
SATA was introduced in order to help improve performance and cope with evolving storage needs. Some key advantages of SATA compared to PATA:
- Faster interface speeds – 1.5 Gbit/s initially and up to 20 Gbit/s for latest SATA revisions
- Thinner cabling allowing better airflow and neater builds
- Native hot swapping support
- Better scalability to support RAID configurations
Because of these benefits, SATA began displacing PATA starting in the early 2000s. By the late 2000s, SATA had effectively superseded PATA, with PATA being phased out on motherboards and storage drives using the newer SATA interface.
Is PATA completely obsolete?
Nowadays, PATA is considered obsolete technology. Almost all modern computers and storage devices use SATA interfaces exclusively. However, PATA is still used in some niche applications:
- Very old computer hardware still relying on PATA drives
- Specialized industrial equipment and automation systems built long ago
- Some retro computing hobbyists may use PATA drives
So while PATA is essentially obsolete in mainstream consumer computing, it still lingers on in some legacy and niche applications where older hardware remains in use. But for most users and organizations, PATA is a relic of the past.
Ongoing relevance of the ATA standard
While PATA may no longer be used, ATA remains very relevant as a storage interface standard. SATA retains broad compatibility with the ATA software/firmware command sets. This provides continuity despite the physical interface changing from parallel to serial connections.
For example, hard drives still appear as master/slave with device IDs under SATA, just as with PATA. Operating systems and programs can still access SATA devices using standard ATA command protocols. And features like SMART drive health monitoring are present on SATA drives just like with late-version PATA drives.
In this sense, ATA is still very much alive as a storage standard – it just takes the form of SATA rather than PATA in most modern computing devices and systems.
The evolution continues from SATA to NVMe
Just as SATA replaced PATA, a newer storage technology called NVMe (Non-Volatile Memory Express) is gradually taking over from SATA as the latest interface standard.
NVMe uses the PCI Express bus rather than SATA, allowing for even faster speeds, lower latency and improved performance especially for solid state drives. NVMe first emerged in 2014 and has been steadily gaining adoption, especially on high-end PCs and servers.
As with the transition from PATA to SATA, NVMe and SATA will likely co-exist for several years. But NVMe is expected to eventually supersede SATA, especially for solid state storage, due to its superior performance.
This means while the physical connections continue to evolve, ATA remains the command protocol used to communicate with storage devices attached to modern computers. The ATA standard has proven remarkably adaptable and has remained a constant from the days of PATA through to SATA and now NVMe interfaces.
Conclusion
In summary:
- PATA is now obsolete outside some legacy hardware and niche use cases
- SATA has fully displaced PATA as the primary disk interface in modern computers
- ATA remains highly relevant as a storage device standard via SATA interfaces
- NVMe is emerging as a higher performance alternative to SATA
So while PATA is essentially extinct, ATA remains very much alive as a vital storage technology standard, even as it continues to evolve from SATA to NVMe interfaces. The ATA command set provides a crucial layer of software compatibility even as the physical connections change over time. This evolution has allowed ATA to maintain its relevance over 30+ years so far.
Should I still use a PATA drive today?
Using a PATA drive in a modern system is not recommended. PATA’s limitations compared to SATA and NVMe make it a poor choice:
- Much slower interface speeds
- Larger cable sizes restricting airflow and component layout
- Lack of hot swapping support
- Poorer integration with modern chipsets and motherboards
A few specific disadvantages of trying to use PATA drives today include:
- Newer motherboards may lack PATA controllers entirely, necessitating an old PATA controller add-in card
- Mixing PATA and SATA can complicate boot order and drive detection
- Finding replacement PATA drives can be difficult and expensive
- May experience degraded performance and compatibility issues
The only real case where using a legacy PATA drive could make sense is for certain industrial environments or specialized applications using old hardware that originally depended on PATA drives. For any mainstream usage, SATA or NVMe drives are recommended.
What kind of cables and connections does PATA use?
PATA relies on wide ribbon cables to connect storage drives to motherboard controllers. The cables consist of 40 or 80 parallel conductive wires:
- 40-wire cable for ATA-2 interface and below
- 80-wire cable for ATA-3 and above interfaces
The ribbon cables transmit 16 bits of data simultaneously across the parallel wires. This allows for faster transfer speeds compared to earlier serial interfaces that sent 1 bit at a time.
However, as serial bus bandwidth improved enormously thanks to standards like SATA and PCI Express, parallel buses like PATA became obsolete due to limitations in clock speeds and cable lengths.
In addition to the ribbon cable, PATA uses a variety of power connectors to drive the storage device itself, providing voltages like +5V and +12V DC.
Early PATA drives used Molex connectors. Later, smaller form factor drives adopted Berg power connectors. Different types of hard drives and vendors implemented different power connectors, contributing to complexity of PATA installation.
PATA interface connections
There are three main interface connections in a PATA configuration:
- Host adapter connection – plugs into the PATA port on the motherboard controller
- Drive connector – plugs into the back of the storage drive
- Middle connector – joins the drive and motherboard cables
This middle connector was necessary because the original ATA standard only supported two devices per controller. One device needed to plug directly into the controller, while others daisy-chained off the middle connector. Later versions of ATA removed this two device limitation.
What are the main differences between PATA and SATA?
There are several key differences between the obsolete PATA standard and the newer SATA interface commonly used today:
| Feature | PATA | SATA |
|---|---|---|
| Interface | Parallel (multi-wire) | Serial (single pair of wires) |
| Cable size | Wide ribbon cable | Thin serial cable |
| Max speed | 133 MB/s | 600 MB/s (SATA 3) |
| Hot swappable | No | Yes |
| Power connector | Molex or Berg | 15-pin SATA connector |
In summary, SATA offers major advantages over PATA in speed, cable management, scalability and ease-of-use. SATA has fewer technical constraints and is better suited for modern large storage drives, high demand applications, and advanced features like hot swapping.
Are there any advantages PATA still holds over SATA?
While SATA has largely superseded PATA, there are a couple areas where PATA still holds some minor advantages:
- Simplicity – PATA cables and connections are very straightforward vs. delicate SATA connectors
- Long cable lengths – PATA cables can be slightly longer than SATA before signal degrades
- Legacy support – PATA handles legacy hardware and boot processes better
However, these benefits apply only in niche cases like industrial equipment or retro computing. For most mainstream applications, SATA’s superior performance and features far outweigh these minor PATA advantages today.
What are the main versions of PATA?
The primary versions of the PATA/IDE standard include:
- ATA-1 – Initial version released in 1986 by Western Digital. Transfer rate up to 8.3 MB/s.
- ATA-2 – Released in 1988. Added new modes for faster 16-bit transfers up to 16.6 MB/s.
- ATA-3 – Released in 1997. Supports up to 33 MB/s transfer rates and SMART monitoring.
- Ultra ATA – Also known as ATA-33. Fastest PATA version at 33 MB/s and introduced 80-wire cables.
- ATA/ATAPI-4 – Added support for optical drives and removable storage like CD-ROMs.
- ATA/ATAPI-5 – Unified standard for hard disks and optical drives. Added new command sets.
- ATA/ATAPI-6 – Introduced native command queuing for improved performance.
Each version increment brought new capabilities and performance improvements. But ultimately PATA was superseded by SATA and NVMe interfaces due to physical limitations of parallel bus design.
How does a PATA cable work?
A PATA cable transfers data between storage drives and the motherboard using a parallel interface with 40 or 80 physical wires. This allows it to transmit multiple bits simultaneously:
- 40-wire cable supports 16-bit transfers
- 80-wire cable supports 32-bit transfers
The cables have three main connection points:
- Host adapter attaches to the motherboard’s PATA controller
- Drive connector attaches to the back of a storage drive
- Middle connector links multiple storage drives together
PATA supports both master and slave drive configurations. One drive is attached as master to the end of the cable, while additional drives daisy-chain off the middle connector as slaves.
The cable wires are grouped into several bus lanes for different signals:
- 16 data lanes for actual storage data transfer
- Control lanes for registers, timings, device selection
- Ground wires to reduce interference
When data is sent over PATA, 16 bits travel over the data lanes simultaneously. Control information is sent over separate control lanes.
Conclusion
While the PATA interface is now functionally obsolete, the ATA standard itself remains highly relevant even as it evolves from parallel to serial implementations. PATA provided huge benefits for many years by standardizing how storage devices integrated with computer systems.
ATA continues powering new technologies like SATA and NVMe that push speed and performance boundaries, while maintaining software compatibility. So while PATA itself is fading into history, its legacy lives on through each new generation of the ATA standard.
ATA has proven to be one of the most long-lived and adaptable computer interface standards, powering revolutionary changes in storage technology over three decades and counting.
