PCI Express®: Selecting the Right Bridge for High Performance Applications

PCI Express (PCIe) is the evolution of the PCI standard, which was developed to meet increasing bandwidth and speed requirements, and to upgrade from a parallel bus architecture to a high speed serial point-to-point architecture. PCIe supports faster bus speeds and backwards-compatible PC interconnect support for both chip-to-chip and add-in card applications. PCIe offers many advantages over conventional PCI and PCI/X: It offers higher speed, is scalable from 1 to 32 lanes of 2.5Gbps for a single 80Gbps link, compared to maximum 8Gbps for 64-bit PCI/X at 133 MHz. Additionally as a serial interface, requirements can be met with far fewer physical connections than parallel PCI/X saving on circuit board complexity and space. PCI Express has been widely adopted across all major markets where PCI/X has been traditionally used. Personal computer manufacturers, server, industrial PC, embedded and telecommunications equipment manufacturers are all moving PCI designs to PCIe. PCIe is becoming more ubiquitous in a broad range of applications. PC motherboards now include PCIe as standard and more PCIe slots are expected to be available in place of PCI. Processors and chipsets now provide PCIe interfaces as standard.