In every motherboard generation on AMD's AM4 socket, we have seen a premium motherboard chipset and a more budget friendly chipset play out in the market. For the latest generation, focusing on Ryzen 3000 processors, we only have the X570 chipset in the market right now, and we're expecting to see a B550 chipset and motherboards built on that chipset at somepoint in the future. B550 hasn't been announced yet, but one avid Reddit user has spotted an OEM system built on the B550A chipset in stores. The existance of B550A has been verified by an AMD employee.

AMD’s B550A chipset belongs to the company’s Promontory-LP family (B450) and therefore supports 2+4 PCIe Gen 3 lanes, two USB 3.2 Gen 2 links, and six USB 2.0 connectors. The chipset is supposed to support overclocking, but since it is only available to OEMs, it is up to them to support the feature. The key capabilty of the B550A is that is has been validated to support AMD's Ryzen 3000 desktop processors.

One of the interesting things to note here is that AMD’s B550 chipset has not been announced yet. In fact, the existence of the B550A was confirmed by an AMD employee in a Reddit comment. It was confirmed that B550A is an OEM version of one of AMD's chipsets based on that Promontory-LP hardware. It is unknown at this point if B550 will act more like B550A, or rather like X570.

Image from Reddit

In the meantime, there a couple of words to say about OEMs and rebrands. One of the interesting things about big PC makers is that they demand product refreshes from their suppliers every year, which is why we see rebrandings of previously released products particularly in case of GPUs. To that end, the quiet introduction of AMD’s B550A chipset is not especially unusual, as it seems to only be OEM-bound. If nothing else, issuing a newer Promontory-class chipset for AMD's Ryzen 3000 CPUs gives OEMs another option for building reasonably-priced PCs powered by the latest processors.

Here is what AMD’s Robert Hallock had to say:

“It has a B550A motherboard. This is a version of the PCIe Gen 3 ‘Promontory-LP’ (e.g., X470, B450) chipset specifically for use in pre-built systems (e.g. OEM customers). […] OEMs are customers, too, and they may have different needs and wants than a DIYer. Not every product decision is considered through the lens of a channel product.”

Related Reading

Sources:, Toms Hardware, Reddit

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  • xrror - Tuesday, October 15, 2019 - link

    Considering that you can cross flash some B350 boards with their B450 counterpart and have it still work, I'd take a guess that B550a is just the newest revision in that chipset line.

    And to answer the question: B350 with B450 bios didn't really confer any performance advantage so not worth the time + most peripheral I/O chips change from a 350 to 450 board revision so you can lose functionality from mis-matched 3rd party chips/firmware, so things like fan control, off-chip USB ports, lighting control etc.
  • R3MF - Saturday, October 19, 2019 - link

    What is the significance of mentioning PCIe3 in the title, and then going on to say in the article that it is the same as the B450 promontory chipset?

    My understanding of B450 is that it:
    a) connected to the Ryzen 1000/2000 CPU's via a PCIe 2.0 4x connection
    b) that it only offered PCIe 2.0 connections from chipset to peripheral devices

    B550 boards will obviously offer PCIe 4.0 16x and 4x [from the CPU!]
    But what would make it an interesting upgrade from B450 is if it:
    a) offers a PCIe 3.0 4x connection to the CPU
    b) and offers PCIe 4.0 connections from chipset to peripheral devices

    Why this matters:
    Because we're looking at the next two years of high bandwidth peripherals such as:
    1. USB 3.2 20Gbps
    2. USB 4.0 40Gbps
    3. 2.5 Gb and 5Gb ethernet
    4. mainstream nvme secondary storage (over sata/spinning rust)

    And these high bandwidth peripherals will be exclusively offered with a PCIE 3.0/4.0 connection, not PCIe 2.0!

    So B550 either has the possibility of being really interesting or a generational dead-end.
    I'd love to know which...?
  • R3MF - Saturday, October 19, 2019 - link

    Re: B550 - this should obviously say:
    b) and offers PCIe [3].0 connections from chipset to peripheral devices
  • a5cent - Saturday, October 19, 2019 - link

    To clarify:

    The B550 boards don't *offer* PCIe 4.0 from the CPU. If you inserted a Ryzen 1000/2000 series CPU into a B550 board, you'd still only get a PCIe 2.0 connection between the x16 slot and the CPU. The board doesn't *support* this in any way. It's just some traces which lead from the CPU directly to the PCIe x16 socket.

    Based on the time it's taking AMD and ASMedia to release B550 (and that they are already late considering the matching processors were released months ago), it seems obvious there is more to B550 than just another firmware update (like B450 was over B350). For the reasons you mentioned, I think PCIe 3.0 is guaranteed. Every report I've seen also mentions it will support PCIe 3.0 (like over on Techpowerup).

    I think the only questions we need answered are these:
    - how many PCIe lanes will it support
    - how many USB ports will it support and of what type

    If B550 doesn't support more lanes than B450, then we'll still not see any B550 motherboards supporting two M.2 sockets without some tomfoolery (like downgrading the x16 slot).
  • R3MF - Saturday, October 19, 2019 - link

    It didn't need clarifying, but thank you;

    yes i agree with the logic of what you say and hope it proves true.

  • annahumphries110 - Wednesday, January 22, 2020 - link

    Will these new chipsets support ryzen 3rd gen CPUs?

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