PCI Express (
Peripheral Component Interconnect Express), officially abbreviated as
PCIe, is a high-speed
serial computer expansion bus standard, designed to replace the older
PCI,
PCI-X, and
AGP bus standards. PCIe has numerous improvements over the older standards, including higher maximum system bus throughput, lower I/O pin count and smaller physical footprint, better performance scaling for bus devices, a more detailed error detection and reporting mechanism (Advanced Error Reporting, AER), and native
hot-plug functionality. More recent revisions of the PCIe standard provide hardware support for
I/O virtualization.