Advanced Technology Attachment (ATA) is a disk drive implementation integrating the controller on the disk drive, which frees up space on the motherboard. It is a standard interface for connecting storage devices, such as hard disks and optical drives. There exist several versions of the ATA standard, all of which were developed by the Small Form Factor (SFF) Committee. An early version of ATA was conceived by Western Digital in 1986 and originally named the Integrated Drive Electronics (IDE).
ATA is also known as IDE and supports one or two hard drives, 16-bit interface and PIO modes 0, 1 and 2. ATA-2 supports faster PIO modes (3 and 4), DMA modes (1 and 2), LBA and was marketed as Fast ATA (Enhanced IDE). ATA-3 only included some minor revisions on ATA-2. Ultra-ATA supports DMA mode 3 and runs at 33 MBps. Supported by Intel, Quantum Corporation proposed the ATA/66, that doubled the ATA to 66 MBps. ATA/100 then increased the data transfer rates to 100MBps.
Many synonyms for ATA exist and include Integrated Drive Electronics (IDE), Advanced Technology Attainment Packet Interface (ATAPI) and Parallel ATA (PATA). In 2003, Serial ATA was introduced and the original ATA was renamed Parallel ATA.
SATA’s advantages over the older Parallel ATA interface are that data transfer is faster and it has the ability to remove or add devices during operation. Cables are thinner and allow for air-cooling which makes it work more efficiently. SATA was designed as a successor to ATA and Parallel ATA and it uses a high-speed serial cable.
SATA controllers have Advanced Host Controller Interface (AHCI) as its standard interface. It allows advanced features such as hot plug and Native Command Queuing (NCQ). AHCI is required to be enabled by the motherboard and chipset for the full advantages of SATA to be effective. If AHCI is not enabled, the SATA controller will operate in ‘IDE emulation’ mode.
Windows XP packaged drivers do not support AHCI, but it is implemented by proprietary device drivers. Windows Vista and the current versions of Mac OS X and Linux include native support for AHCI.
SATA has a special connector, eSATA, which is specific for external devices. Increased data transfer rates as high as 3 Gbit/sec per device are supported.