The more frugal Ryzen 3000 adopters out there may want to think twice before sticking with their 300- and 400-series motherboards, as AMD’s Robert Hallock has confirmed with AdoredTV that only X570 boards will support PCIe 4.0. Some older motherboards have received beta BIOS updates that include PCI-e 4.0 options, but AMD is warning against those in light of potential stability issues.
Users today may find a PCIe 4.0 option available in their pre-X570 motherboards. However, users should expect this option to be disabled when final retail BIOSes are released to implement full performance and stability for new 3rd Gen Ryzen processors. As pre-X570 motherboards were not designed with PCIe 4.0 in mind, their designs may be incapable of running PCIe 4.0 signaling with the requisite stability and performance. To ensure a reliable and consistent experience in the field, PCIe 4.0 will not be an option ultimately available to pre-X570 motherboards. Users may continue with a beta BIOS if they desire, but performance and stability cannot be guaranteed.