(1) Short for Peripheral Component Interconnect, a local bus standard developed by Intel Corporation. Most modern PCs include a PCI bus in addition to a more general ISA expansion bus. PCI is also used on some versions of the Macintosh computer. PCI is a 64-bit bus, though it is usually implemented as a 32-bit bus. It can run at clock speeds of 33 or 66 MHz. At 32 bits and 33 MHz, it yields a throughput rate of 133 MBps. Although it was developed by Intel, PCI is not tied to any particular family of microprocessors. Also see PCI-X and PCI Express.