PCI Express

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PCI Express

PCI Express (Peripheral Component Interconnect Express) is a high-speed serial computer bus standard designed to replace the older PCI, PCI-X, and AGP bus standards. It is used to connect various components inside a computer, such as the graphics card, sound card, and network card, to the motherboard.

What does PCI Express mean?

PCI Express (Peripheral Component Interconnect Express) is a high-speed expansion bus standard used to connect peripheral devices to a computer’s motherboard. It is the successor to the Peripheral Component Interconnect (PCI) standard, which was introduced in the early 1990s. PCI Express is a Serial Interface, unlike PCI’s parallel interface, which provides much higher Data Transfer rates.

PCI Express devices communicate with the host system through a single lane or multiple lanes, each capable of transferring data at up to 250 MB/s. Devices can be configured to use one, two, four, eight, or sixteen lanes, providing a maximum aggregate Bandwidth of up to 4 GB/s in both directions.

PCI Express uses a packet-based protocol for data transfer, which ensures reliable and efficient communication between devices. It also supports hot-plugging, allowing devices to be added or removed from the system without shutting down the computer.

Applications

PCI Express is widely used in various technology applications due to its high bandwidth and versatility. It is commonly employed in:

  • Graphics cards: PCI Express is the primary interface for connecting dedicated graphics cards to motherboards, enabling high-performance gaming and graphics processing.
  • Network cards: PCI Express network cards provide high-speed connectivity to wired and wireless networks, supporting data transfer rates of up to 10 Gigabit Ethernet.
  • Solid state drives (SSDs): PCI Express SSDs offer significantly faster read and write speeds compared to traditional SATA SSDs, making them ideal for high-performance Computing and data-intensive applications.
  • Thunderbolt devices: PCI Express is the underlying interconnect technology for Thunderbolt devices, which provide lightning-fast data transfer rates over a single cable, supporting a wide range of peripherals.
  • Virtualization: PCI Express is used in virtualization environments to assign physical PCI Express devices to virtual machines, enabling efficient utilization of hardware resources.

History

The development of PCI Express began in the late 1990s as a collaboration between Intel, IBM, and Dell. The first version of the specification, PCI Express 1.0, was released in 2003, offering data transfer rates of 2.5 GT/s per lane. Subsequent versions have significantly increased the maximum bandwidth:

  • PCI Express 2.0 (2007): 5 GT/s per lane
  • PCI Express 3.0 (2010): 8 GT/s per lane
  • PCI Express 4.0 (2017): 16 GT/s per lane
  • PCI Express 5.0 (2019): 32 GT/s per lane
  • PCI Express 6.0 (in development): 64 GT/s per lane

With each new version, PCI Express has become an increasingly important technology in computing, enabling higher performance and enabling the adoption of new technologies, such as virtual reality and artificial intelligence.