AMD reverses course, will support Ryzen 5000 in old B350 and X370 motherboards

AMD will officially add support for newer Zen 3-based Ryzen processors to old 2017-era motherboards that use its X370, B350, and A320-series chipsets, the company announced today. These motherboards all use the same physical AM4 socket as brand-new 500-series chipset motherboards, but before now they have not officially been allowed to support AMD's newest chips.

This is AMD's second about-face on Zen 3 compatibility for older motherboards. Ryzen 5000-series chips were originally only going to be compatible with 500-series motherboards, but AMD quickly relented and promised to support Zen 3 on 400-series chipsets after that news was received poorly.

AMD says that BIOS updates with AGESA version 1.2.0.7 will enable support for newer Ryzen processors, including the new budget and high-end CPUs that the company is also announcing today.

When the Zen 3 chips were originally released, AMD said that it wasn't supporting those chips on 300- and 400-series motherboards in part because many of them shipped with 16MB BIOS chips that were just too small to store information for every single AM4-compatible CPU. The BIOS updates that have already gone out for some boards, like ASRock's X370 Pro4, do remove support for older pre-Ryzen Athlon A-series AMD processors in the update that adds Zen 3 CPU support. This will likely be the case for most 300-series motherboards that get Zen 3 support, and anyone still using those older CPUs shouldn't install the updates.

Old 300-series motherboards won't support all the same features as newer chipsets, including PCI Express 4.0 support for GPUs and SSDs, as well as newer versions of the USB protocol. Some of the motherboards may also have trouble running the higher-end Zen 3 CPUs at their full performance levels, since newer motherboards also include newer voltage regulator modules (VRMs) and power-delivery systems that have been optimized for power-hungry high-core-count CPUs. That being said, the new 4- and 6-core chips that AMD announced today should be good fits for these older boards.