PCI Express stands for Peripheral Component Interconnect Express. It is also known as PCIe. PCI Express extends and doubles the data transfer speed of the original PCI. PCI Express is a two-way serial connection, carrying packet data along two pairs of point-to-point data lanes.
PCIe was developed in 2004, designed to offer higher performance and higher bandwidth than PCI or AGP. While some standard PCI slots can still be found on motherboards, many users prefer PCI Express for graphics cards.
PCIe slots can speed up the flow of digital information between peripheral devices and the CPU, because it handles some of the computer’s memory bandwidth. The PCI slots had to share the bandwidth, but the PCI-Express slots join together to provide a more direct and faster connection.
PCIe does not require any application or operating system changes, as the identification of devices connected to a PC is determined by the same protocol used by PCI. This software is not compatible with previous versions of hardware. PCIe slots are either shorter or longer than PCI or AGP connectors.
There are 5 PCIe formats:
- PCI Express 1x with a capacity of 250 MB/s is present in most current motherboards.
- PCI Express 2x rated at 500MB/s is less common, reserved for servers.
- PCI Express 4x with a power of 1000 MB/s is also reserved for servers.
- PCI Express 16x with a power of 4000 MB/s present in all modern cards, is the standard equipment for graphics cards. The 16-lane (x16) slot has replaced the Accelerated Graphics Port (AGP) on many motherboards and fits a PCIe graphics card.
- PCI Express 32x rated at 8000MB/s is the same form factor as PCI Express 16x, often used on high-end motherboards for SLI bus power.