Pcie Standard Specification ((top)) -

The most talked-about part of the PCIe specification is the raw data rate. Each new generation doubles the bandwidth per lane.

| Specification | PCIe 1.0 | PCIe 2.0 | PCIe 3.0 | PCIe 4.0 | PCIe 5.0 | PCIe 6.0 | | --- | --- | --- | --- | --- | --- | --- | | Bandwidth per lane | 2.5 GT/s | 5 GT/s | 8 GT/s | 16 GT/s | 32 GT/s | 64 GT/s | | Bandwidth x1 | 250 MB/s | 500 MB/s | 985 MB/s | 1969 MB/s | 3938 MB/s | 7875 MB/s | | Bandwidth x4 | 1 GB/s | 2 GB/s | 3940 MB/s | 7875 MB/s | 15754 MB/s | 31500 MB/s | | Bandwidth x8 | 2 GB/s | 4 GB/s | 7880 MB/s | 15754 MB/s | 31508 MB/s | 63000 MB/s | | Bandwidth x16 | 4 GB/s | 8 GB/s | 15760 MB/s | 31508 MB/s | 63016 MB/s | 126000 MB/s | pcie standard specification

The PCIe specification is defined by its (measured in GigaTransfers per second, or GT/s) and its encoding method , which determines how much raw data becomes usable bandwidth. Heqing Zhu - Data Plane Development Kit (DPDK) | PDF The most talked-about part of the PCIe specification

GT/s (Giga-transfers per second) is not the same as Gb/s. Due to encoding overhead (e.g., 128b/130b in PCIe 4.0/5.0), the effective data rate is slightly lower than the raw transfer rate. Heqing Zhu - Data Plane Development Kit (DPDK)

Let’s break down what the PCIe specification actually is, how versioning works, and why it matters for system architects and hardware engineers.