Stories by Lovest Watson

Explainer: PCI Express pumps up performance

In the past decade, PCI has served as the dominant I/O architecture for PCs and servers, carrying data generated by microprocessors, network adapters, graphics cards and other subsystems to which it is connected. However, as the speed and capabilities of computing components increase, PCI's bandwidth limitations and the inefficiencies of its parallel architecture increasingly have become bottlenecks to system performance.
PCI is a unidirectional parallel bus architecture in which multiple adapters must contend for available bus bandwidth. Although performance of the PCI interface has been improved over the years, problems with signal skew (when bits of data arrive at their destination too late), signal routing and the inability to lower the voltage or increase the frequency, strongly indicate that the architecture is running out of steam. Additional attempts to improve its performance would be costly and impractical. In response, a group of vendors, including some of the largest and most successful system developers in the industry, unveiled an I/O architecture dubbed PCI Express (initially called Third Generation I/O, or 3GIO).

Written by Lovest Watson11 March 05 22:00