Transfer or the more common derivatives Gigatransfer (GT) and Megatransfer (MT) are terms used in computer technology, referring to a number of data transfers (or operations). They are most commonly used for measuring transfer rates (usually as transfers per second, GT/s, MT/s, etc.). 1 GT/s means 109 or one (US/short scale) billion transfers per second, while 1 MT/s is 106 or one million transfers per second. In order to calculate the data transmission rate, one has to multiply the transfer rate by the information channel width. For example if we have a data bus of 8 bytes with transfer rate of 1 GT/s then the data rate would be 8 GB/s.
The units usually refer to the "effective" number of transfers, or transfers perceived from "outside" of a system or component, as opposed to the internal speed or rate of the clock of the system. One example is a computer bus running at double data rate where data is transferred on both the rising and falling edge of the clock signal. If its internal clock runs at 100 MHz, then the effective rate is 200 MT/s, because there are 100 million rising edges per second and 100 million falling edges per second of a clock signal running at 100 MHz.
In the megatransfer range falls SCSI (Small Computer Systems Interface), while newer bus architectures like the Front side bus, Quick Path Interconnect, PCI Express and HyperTransport operate at the rate of a few GT/s.
