What is parallel ATA

Parallel ATA (Parallel Advanced Technology Attachment or PATA) is a standard for connecting hard drives in computer systems. As the name implies, PATA is based on parallel signaling technology, as opposed to Serial ATA (SATA) devices that use serial signaling technology. Parallel ATA dates back to the 1980s. Integrated Drive Electronics (IDE) drives operate in accordance with this standard.

Connections for PATA devices were originally made with 40-conductor flat cables. These were later replaced by 80-conductor cables in which all other conductors are connected to ground, minimizing mutual capacitance (and consequent crosstalk) between the conductors. The maximum viable cable length is 46 centimeters (approximately 18 inches). This means that PATA cables are only practical for use with internal drives.

Parallel ATA was originally called Advanced Technology Attachment (ATA) until 2003 when SATA was introduced. The cable for a SATA connection has seven conductors. These cables are more flexible than PATA cables and can be much longer, allowing the designer more freedom in the physical design of a system. Because there are fewer drivers, crosstalk is less likely to be a problem on SATA than on PATA. The signal voltage is also lower (250mV for SATA compared to 5V for PATA).