This slide illustrates some basic differences between PCI Express and traditional PCI. PCI Express utilizes a high-speed serial bus which uses low-voltage differential signaling to transmit data across the bus. This is a drastic change from the parallel bus PCI employed. PCI Express is also a point-to-point architecture, while PCI is a shared-bus architecture. With the high-bandwidth capability of PCI Express, isochronous data transfer is support, and quality of service (QoS) is much improved over what PCI offered.

