AMD B550 Motherboards Announced: PCIe 4.0 Support for as Little as $100

5/23/2020 Update: We have removed pricing info from the Asus section below at the company's request, as it was apparently sent to us by mistake. You can still find the pricing information on various other sites, as well as some of it in the comment discussion below.

With AMD’s new mainstream Ryzen 3 3000 CPUs hitting our test bench a couple of weeks ago and Vega-packing Ryzen 4000 Renoir desktop chips seemingly waiting in the wings, now is as good a time as any for new affordable AMD motherboards. Board makers have recently been busy rolling out to Intel-based Z490 boards. But those same companies are also about to usher in a slew of B550 boards (announcing today and going on sale starting June 16) for recent AMD processors that bring most of the key features (like PCIe 4.0 support) of the higher-end X570 platform that launched last year at lower price points that start at $100. 

Those who like their PCs to run silently will also appreciate that B550 chipset doesn’t require support for active cooling. The key consideration with B550 is that, while AMD has confirmed the chipset will support future Zen 3 processors, these boards won’t support Ryzen 2000 and earlier processors, or Ryzen 3000 APUs like the Ryzen 5 3400G--at least at launch. While the AM4 socket remains the same, ROM size limitations make it impossible for board makers to include support for all current, future, and past Ryzen processors with a single firmware package. Doubtlessly, there could be a way for code to be written and flashed to the chips to support various chip models. In fact, AMD announced the company was doing something similar to enable Zen 3 and Ryzen 4000 APU support for existing B450 and X470 motherboards. So companies could release future updates to flash these new boards to support older CPUs, but that’s not a feature you should count on. Of course, it’s in the best interest of the motherboard makers for you to just buy a new board. And neither the board companies nor AMD are likely excited to pay for the code to be written and deal with the doubtlessly large support hassle of an increased number of users flashing their BIOS to swap in code for older CPUs--and that’s assuming you have an existing supported CPU to use while flashing the code. 

As such, if you have an older incompatible Ryzen processor (like the Ryzen 5 2600X in the system I’m writing this on), don’t expect to drop it into one of these B550 boards. Regardless, you won’t get PCIe 4.0 support unless you install a Zen 2-based Ryzen 3000 CPU in one of these boards, anyway.

AMD B550 Chipset: Affordable PCIe 4.0 for the Rest of Us

With all that out of the way, what exactly does B550 offer? Here’s how AMD sees it:

In short, you get PCIe 4.0 support through the CPU, delivering enough lanes for fast NVMe storage and the GPU. Also included is dual-GPU support (though that’s a feature with far less appeal in recent years), along with a doubling of the bandwidth of the motherboard’s general-purpose PCIe lanes from the chipset, from 2.0 to 3.0. That increased per-lane throughput allowed AMD to reduce the number of lanes between the chipset and CPU from six PCIe 2.0 lanes to four PCIe 3.0.  

X570 still gives you much more bandwidth on the chipset level, as well as a faster uplink connection from the chipset to the CPU, stepping both up to PCIe 4.0. But for the vast majority of gamers and general-purpose users who will do little more than install a single GPU and one fast SSD, the bus bandwidth and other features provided by the B550 chipset should be more than enough. 

Even support for fast USB 3.2 Gen2 USB carries over from the higher-end X570 side. Of course, as is always the case with mainstream motherboards, just because a feature is supported at the silicon level doesn’t mean it will show up as something you can plug into the final product. So be sure to check the feature list of any B550 motherboard before buying. 

B550 Motherboards: the Full List (So Far)

There will be lots of B550 motherboards to choose from when they officially go on sale on June 12--AMD says there are over 60 in development. But board makers (likely busy with the very recent launch of Z490 motherboards) seemed to still be sorting some of their B550 launch details as we wrote this. Pricing in particular was still largely undisclosed the day before this announcement, though AMD . We’ll add to this story when we hear of more models, but for now here are all the upcoming B550 motherboards we know about, from the usual suspects: ASRock, Asus, Biostar, Gigabyte, and MSI. 

ASRock B550 Motherboards

Asus B550 Motherboards

Biostar B550 Motherboards

Gigabyte B550 Motherboards

MSI B550 Motherboards