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ASRock's B550AM-Gaming Motherboard Features PCI-Express 4.0 & Beefy VRMs

(Image credit: KOMACHI_ENSAKA Twitter)

Update 02/14/2020: Clarified that this motherboard has been available in OEM systems for several quarters. 

Original Article:

Courtesy of hardware leaker KOMACHI_ENSAKA, we've got images and documentation for one of ASRock's OEM Micro-ATX motherboards that has been used in OEM systems for several quarters: the B550AM Gaming.

It must be noted that while the new upcoming chipset might be called B550, this particular motherboard looks to be a B550A board, which are OEM boards as confirmed by AMD in October last year. In fact, this is the same motherboard as was spotted in October.

Where things get a little confusing is that at that time, the B550A chipset was said by AMD's Robert Hallock to be a rehash of the B450 chipsets but for OEMs, only featuring PCI-Express 3.0. The specifications we found now, however, point to the motherboard having PCI-Express 4.0 for the first PCIe slot, provided the chip supports it. Therefore, it's possible there may be only one B550 chipset, and that the "B550A is for OEMs" argument was meant to throw the community off.

PCI-Express 4.0 was rumored, but not certain, to arrive on the B-series platform. The PCI-Express 4.0 support isn't quite as extensive as on the X570 motherboards, though it's unlikely to affect customers interested in these boards.

Whereas the X570 motherboards have PCI-Express switching that brings PCI-Express 4.0 lanes to all the PCI-E slots, and can split them across multiple slots if necessary, the B550AM Gaming from ASRock only delivers PCI-Express 4.0 support on the uppermost slot and to the M.2 slot. The second PCI-Express slot might look like an x16 slot, but on this Micro-ATX motherboard will only fuel four lanes of PCI-Express 3.0 via the chipset. Most people don't use more than one graphics card, so chances are that these limitations won't affect many. Those who do need more options can opt for the X570 or better motherboards.

(Image credit: KOMACHI_ENSAKA Twitter)

The single M.2 slot is also fully-enabled, supporting four lanes of PCI-Express 4.0 with Ryzen 3000-series CPUs.

Aside from the PCI-Express support, the other thing that stands out is the VRM implementation. On B350 motherboards, VRM implementations are known to leave users wanting. Some of the B450 models bumped the VRM designs up a bit, but most still weren't great. However, this ASRock B550AM Gaming motherboard is packed with a whopping 10 VRM phases using ASRock's Digi power design, and there is also a hefty heatsink on them for cooling. That's a level of VRM circuitry that we've only seen on the higher-end X-series chipsets in recent year.

This is good news for buyers looking to build a new system and don't need the full plethora of connectivity and expansion offered by the X570 motherboards, but who do want a motherboard with good VRM circuitry. Paired with PCI-Express 4.0 support with the right CPUs installed, if we end up seeing more B550 boards in the DIY space with this kind of VRM implementations, we could see the mid-tier B-series chipset group gaining serious traction.

  • Gillerer
    The specifications we found now, however, point to the motherboard having PCI-Express 4.0 on all fronts.

    More like it supports PCIe 4 for connections between the CPU, GPU (in the primary slot), and the primary M.2.

    The motherboard itself doesn't have PCIe 4 (meaning the chipset doesn't).

    The B550A is a rebranded B450, with the difference being that the motherboards using it will be designed with good enough PCIe routing to support PCIe 4 (from the CPU), and the AGESA doesn't lock out gen 4 on the CPU's PCIe controllers.

    Gamers Nexus bought a prebuilt with it and ran some tests:

    "AMD "B550" Chipset vs. B550A, B450 Explained: ASRock B550AM Gaming Benchmarks"
    a YouTube video by Gamers Nexus, from 2020-02-13:
    mBympJkflksView: https://www.youtube.com/watch?v=mBympJkflks
    Reply
  • x4130
    Alienware’s specs for the Aurora Ryzen Edition back this up as well- B550A chipset, PCIe 4.0 only available on the M.2 and top GPU slot via CPU (and only PCIe 3.0/4.0 x8 for the GPU in their case, meaning a 2080 Ti leaves almost half its theoretical bandwidth on the table in that rig).

    B550A on its own does NOT appear to support PCIe 4.0.
    Reply
  • Gillerer
    All the Aurora Ryzen Edition models I can see have 8GB+ VRAM.

    PCIe Gen 3 x8 bandwidth only becomes a bottleneck if you're VRAM-starved, and the driver needs to augment it with system memory a lot.

    That's why it reduces performance on the 4GB 5500XT, but not the 8GB model (and then only on high settings).

    If you have plenty of VRAM, you won't see an appreciable difference. (And I think 11GB for the 2080Ti is always enough; depending on settings and resolution - ones you'd be wanting to use on an 5700/XT - so is 8GB).
    Reply
  • x4130
    Very fair point about the VRAM; I still have some “not getting what you’re supposedly paying for” annoyance with Alienware for some of their their internal hardware decisions, but you’re right that it likely makes no difference in FPS out to a monitor.

    Unrelated, looks like they’ve updated the article to acknowledge the CPU-only PCIe 4.0 aspect.
    Reply
  • Gillerer
    Continued...

    Gamers Nexus has now published Buildzoid's VRM analysis video on this board:

    "AMD "B550" PCB Quality Analysis: ASRock B550A M Gaming Motherboard"
    a YouTube video by Gamers Nexus, from 2020-02-22:
    8bZWHe-7Dlo:0View: https://www.youtube.com/watch?v=8bZWHe-7Dlo&t=0s

    This news piece's hot-take analysis (read: "guess") of the VRM:
    However, this ASRock B550AM Gaming motherboard is packed with a whopping 10 VRM phases using ASRock's Digi power design, and there is also a hefty heatsink on them for cooling. That's a level of VRM circuitry that we've only seen on the higher-end X-series chipsets in recent year.
    is wrong.

    This has the same base cheap 8+2 phase power delivery design of the low-end ASRock X570 motherboards, only with many of the filtering bypass capacitors stripped (around half of them).

    It's still ok for a prebuilt, because this is "a motherboard that's only ever going to run at stock" and "realistically no one is going to overclock on this board" (as per the video).

    So really, adapting the wording of the original news article, this is a level of VRM circuitry worse than any ASRock put out for X570, and only suitable for stock operation.

    This is absolutely not for people who want good VRM. The article should be corrected on that part, so people aren't misled.
    Reply