PCI Express (PCIe) is a standard interface for connecting devices in a computer, where “x16” and “x8” respectively represent the number of data channels that a PCIe slot has. According to the results of PCIe sampling tests conducted by foreign technology media TechPowerUp on the GeForce RTX 4090 and Core i9-13900K platforms, the performance difference between “x16” and “x8” is 2%.
PCIe Gen4 x16 has 16 data lanes; PCIe Gen4 x8 has 8 data lanes. In theory, the performance of PCIe Gen4 x16 should be twice that of PCIe Gen4 x8, but this is not the case.
TechPowerUp has tested some new games that support ray tracing including “Eirden’s Circle” and “Far Cry 6” on the GeForce RTX 4090 GPU and Core i9-13900K CPU platform, showing that the performance difference between Gen4 x16 and x8 modes is very small, The biggest difference is “Far Cry 6”, reaching 8.3%.