According to AMD's board partners, select A320 & X370 motherboards will feature full support for AMD Ryzen 5000 Desktop CPUs while Gigabyte and ASUS have already released BIOS support for the Zen 3 based processors in BETA version (via @Harukaze5719)
AMD Board Partners Showcase Ryzen 5000 Desktop CPUs Running on A320 & X370 Motherboards, Selective BETA-BIOS For ASUS & Gigabyte B450 Motherboards Out Now
The report comes from various forums where users have already got access to BETA BIOS for the A320 & X370 motherboards which allows support for AMD Ryzen 5000 Desktop CPUs. According to a member of Chiphell Forums, the AMD 300-series motherboards can fully support the Ryzen 5000 series processors and one such sample has been shown running on an entry-level ASRock A320M-HDV motherboard.
The motherboard was shown running an AMD Ryzen 9 5900X 12 core processor along with 16 GB of DDR4 memory and even supports AMD's Ryzen 4000G Renoir APUs. It looks like motherboard makers already have BIOS's for X370 & A320 motherboards in the works but we don't expect them to roll them out anytime soon since AMD has officially stated that Ryzen 5000 Desktop CPUs will be only supported by 400 and 500-series motherboards.
Another forum member at Overclock.net, Brko, has revealed that Gigabyte already has Ryzen 5000 CPUs working on its X370 motherboards. Talking to board makers, I confirmed that the BETA BIOS is included with the existing AGESA 18.104.22.168 code. The motherboard fully supported the Ryzen 5000 CPU but had PCIe Gen 4 disabled.
We have already stated about certain motherboard makers allowing AMD Ryzen 5000 Desktop CPU support even on 300-series motherboards. Sure the capacity of the ROM is a major limiting factor and will remove support for other generations, including Ryzen 1000 Desktop CPUs but if you are upgrading to a new processor, then support for older processors doesn't matter much in the first place. AMD seems to be blocking AIBs but we are receiving more and more reports that these BIOS firmware will be released at some point very soon.
In similar news, Gigabyte and ASUS BIOS support for AMD Ryzen 5000 Desktop CPUs are already out. Gigabyte is offering BETA support on a total of 16 B450 chipset based motherboards while ASUS is offering BETA support on a total of 16 ROG STRIX, PRIME & TUF Gaming products. Gigabyte BIOS is titled at F60c whereas ASUS's BIOS is listed as 8501.
If you own a B450 motherboard from either manufacturer and plan on upgrading to an AMD Ryzen 5000 Desktop CPU and don't want to wait till January 2021 for the official support, you can grab the BIOS from the following links for your specific motherboard (via HKEPC):
ASUS B450 (AMD Ryzen 5000 Desktop CPU) BIOS Firmware:
Gigabyte B450 (AMD Ryzen 5000 Desktop CPU) BIOS Firmware:
We have also talked to other board partners and they are already working on a new BIOS for all 400 and 500 series motherboards which should be available by end of year and offer improved compatibility and a list of fixes for AMD Ryzen 5000 Desktop CPUs. We will keep you posted if we hear more regarding A320, X370 & B450 support from partners.