PCIe 4.0 (Peripheral Component Interconnect Express 4.0) is the fourth generation of the PCI Express interface standard, introduced by the PCI-SIG in 2017. It doubled the data transfer rate of its predecessor, PCIe 3.0, providing 2 GB/s per lane in each direction, or 4 GB/s for a full duplex connection. In a 16-lane configuration (x16), PCIe 4.0 delivers an impressive 64 GB/s total bandwidth. This advancement was essential for supporting high-performance applications, such as AI training, data analytics, and 4K gaming, which require significantly increased throughput.
https://en.wikipedia.org/wiki/PCI_Express
One of the significant features of PCIe 4.0 is its improved signal integrity and reliability, achieved through enhanced channel design and new equalization techniques. These improvements allowed the interface to maintain its backward compatibility with earlier versions like PCIe 3.0 while delivering higher performance. The increased bandwidth of PCIe 4.0 has been particularly beneficial for next-generation SSDs and high-performance GPUs, enabling faster data transfer rates for applications such as video editing, rendering, and scientific simulations.
https://pcisig.com/specifications/pciexpress/base
The adoption of PCIe 4.0 has been widespread across consumer, enterprise, and data center environments. It is commonly found in modern motherboards, AMD Ryzen processors, and NVIDIA GPUs. While newer versions like PCIe 5.0 and PCIe 6.0 have since been introduced, PCIe 4.0 remains a popular choice due to its balance of performance and cost, supporting a wide range of workloads with its ample bandwidth capabilities.