PATA, also known as Parallel ATA (Advanced Technology Accessory), is a type of internal computer port that connects to hard drives and other devices. It has been superseded by the faster and more elegant port technology known as Serial ATA or SATA. Virtually all devices now comply with the SATA standard.
A computer motherboard.
Originally, PATA was known simply as ATA (pronounced by jingling the letters). The ATA standard has evolved into many flavors, with each subsequent type increasing data transfer rates. It wasn’t until the serial flavor of ATA came along that the original parallel standard became known retroactively as PATA.
PATA devices are easy to identify by the large 40-pin port that connects to a Parallel ATA cable. These cables are flat, wide, flat cables with 40 parallel strands, hence the designation parallel. Data is divided into lanes and travels in parallel between the PATA controller and the connected device in a master/slave configuration. Cables were later increased to 80 threads to break the data transfer limit reached with the 40 thread flavor of Parallel ATA known as ATA/33. The first iteration of 80 threads was ATA/66 with a transfer rate of theoretical maximum data of 66.6 megabytes. per second (MBps), or double ATA/33.
The cables have a maximum barrier length of 18 inches (46 cm) and require 5 volts of power. One side of the PATA cable has a red line to indicate the pin one layout, useful when connecting the cable to a compatible device. The death of PATA, however, was that it reached a data transfer ceiling of 150 MBps.
SATA cables can be up to 1 meter long, are very narrow, and require only 250 millivolts of power. The first version of SATA was as fast as ATA/150 (150 MBps), but used only a fraction of the power required by PATA, which also allowed more airflow through the case. SATA II increased the data transfer rate to 300 MBps and more specifications followed. Older motherboards that only have PATA slots can run SATA devices using a third-party SATA controller that will fit into the slot, allowing an upgrade to SATA without upgrading the motherboard.
During the interim move to SATA, motherboards often had both types of ports and controllers. One PATA port can control up to two legacy devices in parallel. SATA uses peer-to-peer (rather than master/slave) technology, so one of its ports controls a device. Motherboards are made with multiple SATA ports to accommodate large amounts of data storage and optional RAID configurations. SATA devices are also hot-swappable, unlike PATA devices.
