The terms mega transfer (MT, 106 transfers) and giga (GT, 109 transfers) are used in computer hardware to indicate the speed of a connection. For example, mean 4 GT / s that 4 × 109 ( four billion ) transfers can be performed per second. The data transfer rate thus achieved depends both on the amount of data per transfer from, on the other hand by the number of used parallel lines (lanes). Moreover, the overhead in the use of coding (eg error correction ) must be considered.
For example, PCI Express 2.0 allowed per lane 5 GT / s and uses the 8b10b code for signal transmission, the 8-bit data encoded in 10 bits. A transfer consists of a single bit. One slot for graphics cards is usually connected with 16 lanes. The maximum possible data throughput is then: