Parallel transmission is unreliable and complicated.īoth serial and parallel transmissions have advantages and disadvantages. Serial transmission is reliable and straightforward.The cables used in serial transmission are thinner, longer, and more economical compared to the cables used in parallel transmission.Parallel transmission is ‘half duplex’ since the data can be sent or received at any given time. Serial transmission is ‘full duplex’ since the sender can send and receive data at the same time.Serial transmission is slower since data flows through a single line conversely, parallel transmission is faster since data flows through multiple lines.There are more errors and noise in parallel transmission, since the transmission is done multiple bits at a time. There are fewer errors and less noise in serial transmission, since the transmission is done one bit at a time.Parallel transmission requires multiple lines to send data. Serial transmission requires a single line to send data.Number of bits transferred per clock pulseĭifferences between Serial and Parallel Transmission Comparison between Serial and Parallel Transmission Basis for Comparisonĭata flows in multiple directions, 8 bits (1 byte) at a time Most printers are within 6 meters (about 20 feet) from the transmitting computer, and the slight cost for extra wires is offset by the added speed gained through the parallel transmission of data. With this in mind, the speed of transmission is considered less important when compared to the economic advantage of serial transmission.Īn example of parallel mode transmission is a connection established between a computer and a printer. In this example, a computer may be far from the modem, making parallel transmission very expensive. The two data wires run using the simple serial transmission in either direction.

An RS-232 cable can accommodate 25 wires, but only two of these wires are for data transmission the rest are designated for overhead control signalling. One example of serial mode transmission is a connection established between a computer and a modem using the RS-232 protocol. Parallel transmission can take place within a computer system, through a computer bus, or to an external device located nearby. Serial transmission occurs between two computers, or from a computer to an external device located far away. 5 lines – communicate and notify errors.It uses a 25-pin port with 17 signal lines and 8 ground lines. It transmits quickly as it utilises several input and output lines for sending the data. Several bits are transmitted simultaneously with one clock pulse rate.

Advantage of serial processing