The PCIe gen 4 is the next evolution of a widely used, high-speed interface. PCIe 4.0 has double the throughput of PCIe 3.0. The PCIe 4.0 is structurally similar to the PCIe 3.0 and they key difference is the higher transfer rate, material used to achieve successful transmission of the PCIe signal.
The PCIe 4.0 use a 128b/130b encoding technique whereas the old generations use 8b/10b encoding. This encoding transforms 128-bit data into 130-bit line code which allows reasonable clock recovery and ensures alignment of the data stream. the maximum theoretical bandwidth in Gbps (Gigabit per second) of each PCIe Gen 4.0 is 15.754 Gbps. The increase in bandwidth enables faster data transmission between PICe and endpoint.
The PCIe is backward and forward compatible which means that it can be used as a direct replacement for PICe 3.0 and also PCIe 3.0 will perform to the PICe 3.0 specs if used in PCIe 4.0 slots. The PCIe 40.0 would allow quicker transfer of the data being loaded in the GPU’s memory and decreased latency on the PCIe bus. In order to get the full benefit of the new technology, PCIe 4.0 should be used in a 4.0 motherboard with a compatible CPU.
PCIe 4.0 is simply considered the next generation of the interface standard by which certain components, specially graphics cards and solid state drives, connect to your system. With few PC’s currently supporting PCIe 4.0 it states that will grow into its utility in the coming years as drives, GPUs and other components continue to get faster.