Serial advanced technology attachments (SATA) work by transmitting data between a motherboard and hard drives through a seven-pin cable that sends information twice as fast as previous technology, according to About.com. A single high-speed serial wire now inhabits most computer systems instead of a parallel bus system that incorporated 40-pin wires or 80-pin wires.
SATA cables transmit data at a higher clock rate than parallel bus systems. A clock rate is how fast a CPU executes instructions, therefore SATA cables handle faster CPU speeds than parallel cables. SATA lines transmit data up to 3 gigabytes per second to keep up with faster CPUs.
Serial wires use two lines for sending data and two lines for receiving data. Three lines are ground wires, which adds up to the seven wires and pins in a SATA cable. Serial wires take up less space than parallel ones, thereby making more space for hardware in desktop and laptop computers. SATA cables have allowed computer hardware to get smaller and faster as compared to parallel systems.
Older parallel systems were replaced because processor speeds increased. When speeds increased, interference in the lines also increased. Serial transmissions use just one line instead of several parallel lines, so interference is minimal.