Better late than never. AMD would be releasing AMD B550 motherboards that are PCIe 4.0 compatible on June 16th of this year. The B series motherboards are often lower priced products compared to the X series. That does entail less features and dimmed down specifications.
However, the reality is that most people are fine with an X16 slot, one M2 slot, two DIMM slots and a bit of audio to build a cost-effective gaming or internet PC. Back to the rumor though as it is just that, earlier on in the year it was Digitimes that claimed a release later this year, new chatter from unconfirmed industry sources, however, indicates the new June 16thy launch. And yes, we've already witnessed a few B550 leaks of course.
B550 would do with one M2 slot, however directly connected to the CPU with an x4 PCIe Gen 4.0 link. B550 chipset looks familiar to X470. Meaning PCIe Gen 3.0 is the biggest change compared to X570. That also means the interlink between the chipset and CPU is running over four Gen 3 lanes. The good news is that with four extra Gen 4 lanes from the CPU, you can still opt to go with an M2 PCIe 4.0 slot. The rest, say for your video card thus is Gen 3.0.
| Chipset | End-user | USB 3.2 Gen 2 | USB 2.0 | SATA3 | Interconnect | OC Support |
| B550 | Mainstream | 2 | 6 | 4+4 | x4 Gen3 | Yes |
| X570 | Enthusiast | 8 | 4 | 4+8 | x4 Gen4 | Yes |
Compared to the top-end X570, it offers fewer USB 3.2 Gen2 (10 Gb/s) ports, does not support PCI Express 4.0 from the chipset, and communicates with the Ryzen processor via four PCI-E 3.0 lines (instead of PCI-E 4.0), which limits the total bandwidth controllers built into it. So only one M2 slot would do PCIe Gen 4.0.
AMD B550 motherboards with M2 PCIe 4.0 support would launch June 16th
