PCIe development has progressed from the original 1.0 to 6.0. However, many people know about PCIe without understanding its essence. Today, the author will take you to explore. To understand what PCIe is, we first need to discuss what a bus is. If we consider the motherboard as a city, then the bus is like the city’s public bus, which follows a fixed route to continuously transport bits back and forth.

PCIe belongs to high-speed serial point-to-point dual-channel high-bandwidth transmission. The connected devices are allocated dedicated channel bandwidth, not sharing bus bandwidth. It mainly supports active power management, error reporting, end-to-end reliable transmission, hot-plugging, and quality of service (QOS) functions. PCIe’s main advantage is its high data transfer rate, and it has significant development potential.

PCIe also comes in various specifications, such as x1, x4, x8, x16, and x32, where the number following ‘x’ represents how many channels the PCIe slot has (how data enters and exits the PCIe card). A PCIe x1 slot has one channel and can transmit one bit of data per cycle. A PCIe x2 slot has two channels, allowing it to transmit two bits of data per cycle (and so on).