BIOSTAR has confirmed Ryzen 3000 support for previous 300 (X370, B350, A320) and 400 (X470) series motherboards. Two other vendors have also confirmed support with those vendors being ASUS and ASRock.
Ryzen 3000 - A320/B350/X370/B450/X470 Support
BIOSTAR has published a list of motherboards that will have Ryzen 3000 support. AMD pledged to support the AM4 platform for the long term, and it seems BIOSTAR has also committed to doing the same for the full range of motherboards, therefore, all previous chipsets including A320, B350, B450, X370, and X470 will support Ryzen 3000.
A common question floating around recently was whether or not A320 motherboards would support Ryzen 3000, and this has been answered. Five A320 motherboards from BIOSTAR will support Ryzen 3000 CPUs, but those would be the ones with onboard Vega graphics and not 7nm Zen 2 cores.
- A320MH PRO
- A320MD PRO
B350 motherboards will support Ryzen 3000, but it is unclear whether certain features will be held back similarly to Precision Boost 2.0 and Precision Boost Overdrive. At this time, there is no indication of future PCIe 4.0 support for B350 motherboards.
- Hi-Fi B350S1
B450 motherboards are in a similar situation as B350 motherboards and may be somewhat featured limited.
There is a possibility of X370 motherboards receiving support for PCIe 4.0. Due to Zen 2's integration of PCIe lanes, older X370 motherboards may receive the ability to utilize Zen 2's PCIe 4.0 capabilities. X370 may not take advantage of SenseMI improvement either.
X470 motherboards also have the possibility to receive limited PCIe 4.0 capabilities, though, similar to X370, SenseMI improvements may not be utilized.
Recently, a future BIOSTAR motherboard has been leaked:
The X570GT8 seems to be a solid option for Ryzen 3000. The X570GT8 features a 12-phase VRM, active chipset cooling, and DDR4-4000+ OC support.
X570 motherboards may receive full PCIe 4.0 support with a total of 40 PCIe 4.0 lanes when paired with Ryzen 3000 CPUs.
MSI and ASRock have teased upcoming X570 motherboards.