Acronym for Peripheral Component Interconnect, a local bus computer standard developed by Intel Corporation. Most modern PCs include a bus that is only PCI capable; early PCI designs incorporated the PCI bus in addition to a more general ISA expansion bus. Those are now called Legacy capable motherboards. Many analysts, however, believe that PCI will eventually supplant ISA entirely (as of April 2002, it has not completely but is well on the way); it appears that non ISA systems are now the norm rather than the exception in the year 2000. PCI is also used on newer 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, 66, 100 and 133 MHz. At 32 bits and 33 MHz, it yields a throughput rate of 133 MBps. Board pin density is also greater and for confusion avoidance, boards will not interchange in ISA and PCI slots. Although it was developed by Intel, PCI is not tied to any particular family of microprocessors.