This bus specification is initially due to Intel who started work to 90. Version 1.0 is released June 22, 92 and the 2.0 30 April 93. The first implementation date of 94 on motherboards for processor Intel 80486. From there, the bus PCI quickly replaces the other present bus as the bus ISA.
The revision 2.1, including specifications for the 66 MHz bus, released in 95.
Since then, the evolution of the specifications of the bus PCI, as well as those of the bus AGP and of the PCI Express are managed by an interest group, the PCI Special Interest Group (PCI-SIG)open to industrialists.
Since 2004, for devices fast (such as graphics cards), the bus PCI (and the) AGP ) is replaced by a smaller and faster version : the PCI Express.
2.34 PCI which exists in two versions :
-32-bit bus at 33 MHz (133 MB/s maximum bandwidth) 1 (the most common);
-bus 64 bits at 66 MHz (528 MB/s maximum bandwidth) 1, used on some professional motherboards or servers (they are twice the length of the) PCI 2.2 32-bit bus);
PCI-X : bus 64-bit 133 MHz (i.e. a maximum bandwidth of 1066 Mb/s), used primarily in Professional machines;
PCI-X 2.0 : 266 MHz (or a maximum bandwidth of 2133 MB/s);
PCI Express : standard derived from the PCIintended to replace in personal computers. Although intended to replace the bus AGP (but also the) PCI), the PCI Express is not limited to the single plug in video card;
Mini PCI : derivative of the PCI 2.2 intended to be integrated into laptops.
In his version purely PCI the bandwidth is shared between all of the elements connected to the bus, unlike what happens for the PCI Express version where it is dedicated for each device. This last is preferable if one wants to use simultaneously maps high flow (Gigabit network card, disk controller, graphics card).
As for processors, some motherboards allow to surfrequencer a bus PCI at 33 MHz, by increasing the frequency of the bus up to 37.5 MHz or 41.5 MHz. Despite the gap in the standard of many maps PCI still function perfectly (and faster) at these frequencies.
Connectors PCI are commonly found on motherboards number of 3 or 4 to a minimum and are usually recognizable by their white color (standard).
The interface PCI available in 32 bits, with a connector, 124 pins, or 64-bit with a 188-pin connector. There are also two levels of signaling :
-3.3V, intended for laptops
-5V, intended for desktop computers
Signaling voltage does not match the power supply of the card but the thresholds for voltage for digital encoding information.
Connectors PCI 64-bit offer additional pins, but can accommodate the PCI 32-bit card. There are 2 types of 64-bit connectors :
-Connector PCI 64-bit, 5V
-Connector PCI 64-bit, 3.3 V