The Peripheral Component Interconnect (PCI) bus was developed by Intel on 22 June 1992. Unlike the VLB bus, this is not, strictly speaking, a local bus but an intermediate bus between the processor bus ( NorthBridge) and the I / O bus (SouthBridge) PCI slots are generally present on the motherboards at least 3 or 4 and are generally recognizable by their white (normalized) color. 32-bit, with a 124-pin connector, or 64-bit, with an 188-pin connector. There are also two signal levels: 3.3 V and 5 V. The signaling voltage does not match the signal voltage, But at voltage thresholds for the digital coding of the information.
The Peripheral Component Interconnect Express (PCI-E) or 3GIO ( “Third Generation I / O”) bus is an interconnect bus for adding expansion cards to the computer. The PCI Express bus was developed in July 2002. Unlike the PCI bus, which operates as a parallel interface, the PCI Express bus operates as a serial interface, resulting in a much higher bandwidth than the PCI Express bus.