AMD Radeon RX 6400 Tested on PCI-Express 3.0 @ TechPowerUp
 

AMD is using a fairly narrow PCIe x4 interface on their Radeon RX 6400 GPU. We're taking AMD's new budget offering for a spin in a PCI-Express 3.0 configuration, to determine how big the performance hit will be when running on an older system.

https://www.techpowerup.com/review/a...ss-30-scaling/