The PCI Express
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‘The PCI Express’: Understanding In Detail

The Peripheral Component Interconnect Express most commonly known by its abbreviation PCIe (mistaken as PCI-E) is a popular hardware interface found in many of the modern computers. It was developed by the Intel Corp. in 2004 and is launched as advancement to the then existing AGP (Accelerated Graphic Port), PCI (Peripheral Component Interconnect) and PCI-X (Peripheral Component Interconnect – Extended) interfaces. In this article we help you understand all the jargon related to the PCI Express in the simplest form.

Why should you know about the PCI Express?

Researchers have always been busy in investing their time and energy in developing speed of processors, the memory and every other devices and components used. But without the development in the external connection interfaces and expansion slots their work would never have been effective. Had there been no such advancements it would have been a really big limitation. So here are a few common type of expansion slots launched throughout the history:


  • ISA (Industry Standard Architecture)
  • MCA (Micro Channel Architecture)
  • EISA (Extended Industry Standard Architecture)
  • VLB (VESA Local Bus)
  • PCI (Peripheral Component Interconnect)
  • PCI-X (Peripheral Component Interconnect Extended)
  • AGP (Accelerated Graphics Port)
  • PCI Express (Peripheral Component Interconnect Express)

So it is the most recent development and is here to stay owing to its advantages for a long time. Hence the knowledge of PCIe is a must.

What exactly is the PCI Express?

The PCI Express

PCI Express is the point-to-point connection interface between your computer and peripherals connected to its expansion slots. It employs serial connection formats and is different from the PCI, AGP or other interfaces which use parallel connection formats. The main difference is that PCIe acts more like a network than a bus and employs high speed serial connection. Due to this fact, the bandwidths of the PCI Express range from 250MB/s (in 1x config.) to a 8000MB/s (in 32x config.).


What is High Speed Serial Connection?

PCI and all other expansion slots except the PCIe use the parallel connection architecture because they are connected to the bus. Due to this reason as the number of devices on the bus increased, the interaction became slower. (Bus is a data path on which several devices can be attached at once and all of them share this common data path). Even if the connection speed increases, there are chances for the wires to electromagnetically interfere with each other.

Due to this reason researchers started working on the slow yet reliable serial connection technologies. In this connection type, data is separated in the form of packets and all these packets are sent at once for place to place. Due to this reason the transfer used to be a tad slow compared to the parallel connection which could transfer data at a time via different channels. But now the highly optimized serial connections owing to several developments have proved to be faster and much reliable than ever.

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