what type of bus does pci express use
PCI Express PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e,[1] 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[2]), and native hot-plug functionality. More recent revisions of the PCIe standard provide hardware support for I/O virtualization.