AMD Reverses Course, Will Enable Zen 3 and Ryzen 4000 Support on B450 and X470 Motherboards

(Image credit: Tom's Hardware)

After receiving withering criticism from its passionate fan base and casual users alike, AMD has reversed its decision to not enable Zen 3 and Ryzen 4000 compatibility with existing B450 and X470 motherboards. Instead, AMD will enable support through optional AGESA code that it will supply to motherboard vendors. However, multiple caveats apply. Here's AMD's quick breakdown, and we also have the full announcement at the end of the article:

  • We will develop and enable our motherboard partners with the code to support “Zen 3”-based processors in select beta BIOSes for AMD B450 and X470 motherboards.
  • These optional BIOS updates will disable support for many existing AMD Ryzen Desktop Processor models to make the necessary ROM space available.
  • The select beta BIOSes will enable a one-way upgrade path for AMD Ryzen Processors with “Zen 3,” coming later this year. Flashing back to an older BIOS version will not be supported.
  • To reduce the potential for confusion, our intent is to offer BIOS download only to verified customers of 400 Series motherboards who have purchased a new desktop processor with “Zen 3” inside. This will help us ensure that customers have a bootable processor on-hand after the BIOS flash, minimizing the risk a user could get caught in a no-boot situation.
  • Timing and availability of the BIOS updates will vary and may not immediately coincide with the availability of the first “Zen 3”-based processors.
  • This is the final pathway AMD can enable for 400 Series motherboards to add new CPU support. CPU releases beyond “Zen 3” will require a newer motherboard.
  • AMD continues to recommend that customers choose an AMD 500 Series motherboard for the best performance and features with our new CPUs.

The new BIOS revisions will enable the full functionality of Zen 3 processors, but you will still not gain access to the PCIe 4.0 interface on B450 and X470 motherboards (they don't support the interface). AMD's initial outline of the upgrade path is a bit nebulous, but the company is frank that these broad outlines will evolve over time.

We're told the company will provide initial AGESA support, which is the underlying boot-up code that motherboard vendors build BIOSes upon, to enable support for Zen 3 processors. However, it is unclear if the AGESA, or the SMU components of the code that optimize performance over time, will also receive periodic updates. As we've seen time and again, AMD's AGESA and SMU updates can improve performance tremendously post-launch, so an ongoing update cadence will be key to receiving the best that Zen 3 processors have to offer. AMD tells us that it will update us on its upgrade plans soon.

Due to the massive number of processors supported with the AM4 socket (the longest-lived desktop socket yet), AMD has constantly battled with SPI ROM capacity limitations. These small chips store the BIOS and associated data that enables chip support, but AMD's ballooning support matrix has already led to split support on some platforms. Motherboard vendors have also de-featured BIOS interfaces on some motherboards, discarding fanciful GUIs and moving to simple text-based menus, to expand the number of supported chips. However, ROM capacity limits are an immutable problem that can only be solved by using larger chips and having processors that can address enough ROM capacity (first-gen Ryzen only supports 16MB), and many motherboard vendors are reluctant to increase capacity because it adds cost (among other factors). As such, the special Zen 3-enabling BIOS revision removes support for previous-gen Zen processors.

AMD says the BIOS updates come as a one-way path: You can flash your motherboard to the new firmware, but you will not be able to flash back to previous BIOS versions that support pre-Zen 3 processors. AMD will also require an as-yet-undefined process that verifies you have purchased a Zen 3 processor. AMD says that verifying a customer has purchased a Zen 3 processor is designed to prevent irreversible BIOS flashing issues, but AMD's reasoning behind the forward-only flash requirement is unclear.

AMD's updates also mark the end of the line for 400-series motherboards: AMD will not support future processors on the platform. The company also confirmed that Ryzen 4000 will land this year. 

Why the Ruckus?

(Image credit: AMD)

Back with the arrival of Ryzen in 2017, AMD committed to supporting its AM4 socket until 2020. That commitment was interpreted by enthusiasts to be a promise for a forward- and backward-compatible platform that wouldn't require the frequent motherboard updates that AMD's primary competitor, Intel, has become known for. In effect, forward- and backward-compatibility essentially lowers the price of upgrading your processor in the future.

With the Ryzen 3 3300X launch last month, AMD announced that while the new Zen 3 processors would continue to drop into the AM4 socket, the company wouldn't enable support for Zen 3 processors on existing X470 and B450 motherboards. While this announcement still stuck to the letter of AMD's original commitment (AM4 socket support throughout 2020), the lack of forward compatibility for previous-gen chipsets sparked a tremendous backlash from the community. That's because many interpreted AMD's commitment to the AM4 socket as a statement that all socket AM4 motherboards and chipsets would provide an easy and relatively inexpensive path forward to AMD's next-gen processors.

You could certainly argue that very few users actually upgrade their CPUs frequently enough to stick with their previous-gen motherboard, instead opting to buy a new motherboard to access all of the new functionality that entails (like PCIe 4.0 on X570 and B550 boards). However, as a result of AMD's decision to cut support, some AMD customers felt their investment in what they considered to be a longer-term platform was wasted.

In either case, AMD's solution, albeit one with plenty of caveats, is a positive development. AMD is frank that its plan is still in the opening stages and will evolve over time, but does reflect that the company listens to feedback from its passionate fan base. That's refreshing.

The full press blast follows: 

As we head into our upcoming “Zen 3” architecture, there are considerable technical challenges that face a CPU socket as long-lived as AMD Socket AM4.  For example, we recently announced that we would not support “Zen 3” on AMD 400 Series motherboards due to serious constraints in SPI ROM capacities in most of the AMD 400 Series motherboards. This is not the first time a technical hurdle has come up with Socket AM4 given the longevity of this socket, but it is the first time our enthusiasts have faced such a hurdle.

Over the past week, we closely reviewed your feedback on that news: we watched every video, read every comment and saw every Tweet. We hear that many of you hoped a longer upgrade path. We hear your hope that AMD B450 and X470 chipsets would carry you into the “Zen 3” era.

Our experience has been that large-scale BIOS upgrades can be difficult and confusing especially as processors come on and off the support lists.  As the community of Socket AM4 customers has grown over the past three years, our intention was to take a path forward that provides the safest upgrade experience for the largest number of users.  However, we hear you loud and clear when you tell us you would like to see B450 or X470 boards extended to the next generation “Zen 3” products.

As the team weighed your feedback against the technical challenges we face, we decided to change course. As a result, we will enable an upgrade path for B450 and X470 customers that adds support for next-gen AMD Ryzen Processors with the “Zen 3” architecture.  This decision is very fresh, but here is a first look at how the upgrade path is expected to work for customers of these motherboards.

1)      We will develop and enable our motherboard partners with the code to support “Zen 3”-based processors in select beta BIOSes for AMD B450 and X470 motherboards.

2)      These optional BIOS updates will disable support for many existing AMD Ryzen™ Desktop Processor models to make the necessary ROM space available.

3)      The select beta BIOSes will enable a one-way upgrade path for AMD Ryzen Processors with “Zen 3,” coming later this year. Flashing back to an older BIOS version will not be supported.

4)      To reduce the potential for confusion, our intent is to offer BIOS download only to verified customers of 400 Series motherboards who have purchased a new desktop processor with “Zen 3” inside. This will help us ensure that customers have a bootable processor on-hand after the BIOS flash, minimizing the risk a user could get caught in a no-boot situation.

5)      Timing and availability of the BIOS updates will vary and may not immediately coincide with the availability of the first “Zen 3”-based processors.

6)      This is the final pathway AMD can enable for 400 Series motherboards to add new CPU support. CPU releases beyond “Zen 3” will require a newer motherboard.

7)      AMD continues to recommend that customers choose an AMD 500 Series motherboard for the best performance and features with our new CPUs.

There are still many details to iron out, but we’ve already started the necessary planning. As we get closer to the launch of this upgrade path, you should expect another blog just like this to provide the remaining details and a walkthrough of the specific process.

At CES 2017, AMD made a commitment: we would support AMD Socket AM4 until 2020. We’ve spent the next three years working very hard to fulfill that promise across four architectures, plus pioneering use of new technologies like chiplets and PCIe Gen 4. Thanks to your feedback, we are now set to bring “Zen 3” to the AMD 400 Series chipsets. We’re grateful for your passion and support of AMD’s products and technologies.

Paul Alcorn
Managing Editor: News and Emerging Tech

Paul Alcorn is the Managing Editor: News and Emerging Tech for Tom's Hardware US. He also writes news and reviews on CPUs, storage, and enterprise hardware.

  • InvalidError
    Irreversible BIOS upgrade that sacrifices compatibility with most CPUs B450 was intended for to enable compatibility with Zen 2. This is going to get awkward on the used market and people who upgrade their 4000-series CPU from a 400-series to a 500-series motherboard and want to put their now unsupported old CPU back into the 400-series board.
    Reply
  • TCA_ChinChin
    Hey that's pretty good. That being said, I think the one way flash forward thing is not a deal breaker at all, provided that AMD can make sure the new AGESA and beta BIOS aren't worse in some way compared to previous versions. I'm curious to see how AMD keeps track of who specifically buys and owns a Zen 3 processor with the relevant B450/X470 motherboards.
    Reply
  • digitalgriffin
    InvalidError said:
    Irreversible BIOS upgrade that sacrifices compatibility with most CPUs B450 was intended for to enable compatibility with Zen 2. This is going to get awkward on the used market and people who upgrade their 4000-series CPU from a 400-series to a 500-series motherboard and want to put their now unsupported old CPU back into the 400-series board.

    Yes but as only enthusiast will do this, I think they realize the implications.

    I have a nice system but it took me over 30 hours to plumb up and wire up with 2 radiators, and 9 case fans all RGB. I'm not in the mood to pull that motherboard and find one that has the exact specs I need, reinstall windows and my software + licenses just to upgrade the CPU. I'm willing to swap a CPU but that's it, especially on a dead end upgrade path. My time is more valuable than that.

    I'm grateful AMD gives us the option. I can't fault AMD if the motherboard makers don't upgrade the ROMs though. There's little benefit for them to do this other than potential customer loyalty for future gens. (MSI certainly has earned it's community support wings for fighting for this with the MAX series)
    Reply
  • DZIrl
    I don't understand why all this hype about BIOS. I mean, I know but there is simple solution. Most users do not know what BIOS is nor access it and other use BIOS few times in their lifetime. BIOS must be as simple as possible, no fancy and useless graphics no one uses. Every PC must boot with default settings and few most used settings should be available, eg RAID, XMP. Everything else needs to be an app or give user possibility to create his own fancy BIOS for specific CPU(s).
    My bigger problem with BIOS (Gigabyte) is that almost every BIOS update destroys current settings and I must go thru every one and enable it. Loading stored setting does not work always.
    Of course, BIOS update without CPU is mandatory and does not cost much - chip 3 cent microcontroller with USB stack.
    Reply
  • daworstplaya
    This is great news! AMD actually listened to the enthusiasts and did what's right. As has been said, most generic users don't know what a BIOS is, let alone how to upgrade it. Those folks will never perform a CPU upgrade either so who cares about split compatibility. Those of us that know how to, we will upgrade the CPU and not look back at backwards CPU compatibility on the motherboard. The old CPU will probably be sold to a friend or given to a family member. This will help AMD sell more Ryzen 3 (Vermeer) CPUs and most importantly has created good will with the enthusiast community.
    Reply
  • st379
    I wonder if the time just before intel 10th gen is a coincidence or it was planned all along.

    Anyway it is good news to people who purchased the MAX motherboard for the purpose of upgrade.
    Reply
  • digitalgriffin
    What I'm curious about is how they will confirm you have a Zen 3 CPU before you update the BIOS?

    Will AMD force you to submit the serial number on the chip? And then give you a key which you can use to unlock the upgrade process? I'm curious how this would work as the MB Vendors would have to add this extra validation step.
    Reply
  • InvalidError
    daworstplaya said:
    As has been said, most generic users don't know what a BIOS is, let alone how to upgrade it. Those folks will never perform a CPU upgrade either so who cares about split compatibility.
    Say that again 2-3 years down the road when these boards end up on the second-hand market. Many people are going to get screwed by the mix of boards that have and haven't been updated, can and cannot be downgraded. It'll be absolutely critical for sellers to accurately list the exact BIOS version that boards will be shipping with.
    Reply
  • digitalgriffin
    InvalidError said:
    Say that again 2-3 years down the road when these boards end up on the second-hand market. Many people are going to get screwed by the mix of boards that have and haven't been updated, can and cannot be downgraded. It'll be absolutely critical for sellers to accurately list the exact BIOS version that boards will be shipping with.

    How big is the used board market? (Out of curiosity. I honestly don't know.)
    Reply
  • InvalidError
    digitalgriffin said:
    How big is the used board market? (Out of curiosity. I honestly don't know.)
    Based on forum posts by people living in poorer countries, sounds like just about all of it in many cases. The APAC region is so desperate for cheap PCs that off-brand manufacturers make motherboards from recycled components because they cannot afford new sockets, chipsets and other major components.
    Reply