When we first talked about Zen 3 some months ago, one of the downsides to the chip was the limited backward compatibility for older motherboards. At the time, AMD indicated they would be able to support a few specific X470 motherboards in the equivalent of a beta-testing program. That guidance has since changed. Not only is X470 support coming to Zen 3, but AMD is also enabling the CPU on the B450 platform as well. Asus has confirmed this, with a specific statement on the topic:
We’ve seen the recent forum posts about X470 and other 400 series boards not being supported by ASUS for 5000 series processors from AMD. This is false information and incorrect.
To clarify, ASUS will follow AMD’s support plan to release a new BIOS on X470, B450 and B450 II motherboards and all those available in the market at present will also be compatible with that BIOS upgrade. Beta BIOS support, following AMD guidelines and timelines means this will be ready to roll out around Jan 2021.
The statement also notes that all new Asus B450 II motherboards will come with BIOS flashback, allowing you to buy a new CPU and use that feature to load a new UEFI. Asus will update on the upgrade situation for other boards closer to the expected January 2021 release date for X470 / Zen 3 support. As always, motherboard vendors will be the ones who determine which boards they update, but the capability will be there.
AMD also has a program that will provide you with a free CPU for flashing your UEFI if you purchase a motherboard that lacks support for a Zen 3 / Ryzen 5000-series CPU. I’ve never taken advantage of it myself, but I personally know someone who has, and the offer worked exactly as advertised. While Asus says it will notify users which motherboards need to be upgraded with an older CPU, anyone planning to upgrade an existing B450 or X470 motherboard should plan to flash the UEFI before you swap CPUs. Don’t take the chance that you won’t have to, especially if you haven’t updated your UEFI since you built your system.
The backward compatibility situation is not perfect — it would have been even better to see support for B350 and X370 — but it’s very, very good. AMD is claiming substantial performance per watt improvements while leaving its TDPs unchanged compared to the last generation. The X470, in particular, is going to be the real performance/watt champion here, especially if you aren’t concerned with PCIe 3.0 as compared with high power efficiency.
It’ll take a few months for support to roll out across the ecosystem, but once it does, this is going to be excellent news for AMD fans. I recently wrote a story illustrating that Ryzen was the fastest-scaling CPU AMD has launched going back to the 1999 debut of K7. It’s also the fastest-scaling CPU compared with any Intel product dating back to the Pentium 4’s brief frequency surge from 2GHz to 3.06GHz with Hyper-Threading from January-November 2002. With this announcement, the X470 seems to be bidding fair as one of the most upgradeable platforms of all time. The X370 got Zen+, Zen 2, and a bump to 16 cores. The X470 got the same 16-core bump, Zen 2, and now Zen 3. AMD’s plan to deliver strong upgradeability year-on-year has been an excellent value-add for its customers, with top-end performance more than doubling in the same socket thanks to the combination of additional core counts and IPC.