Update

AMD Ryzen motherboards explained: The crucial differences in every AM4 chipset

X370, B350, A320, or X300: Which Ryzen motherboard chipset is right for you?

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Credit: Brad Chacos

Editor's note: This article originally published on March 1, 2017, but was updated with additional details, information about scarce mini-ITX availability, and links to AM4 motherboard models after Ryzen's launch.

For AMD’s disruptive Ryzen processors, selecting the correct motherboard is both easier and more crucial than ever.

First, the good news: AMD’s doing away with the frightful hodgepodge of motherboard platforms to unite around the AM4 socket with Ryzen CPUs, Bristol Ridge APUs, and all other chips released in the foreseeable future. Huzzah! But there are a wide variety of chipsets available for AM4 motherboards, and each unlocks different capabilities in your PC, from USB support to overclocking to how many graphics cards you can install.

Should you buy an X370, B350, or A320 motherboard? Where do X300 and A300 fit in? Let’s examine what each AM4 chipset offers so you can make the right decision when you buy a motherboard for your Ryzen 5 or Ryzen 7 processor.

Ryzen: More than just a processor

am4 procs AMD

As you can see in the graphic above, Ryzen—and AMD’s Bristol Ridge APUs—actually resemble a system-on-a-chip design more than a traditional CPU. AMD’s processors integrate support for many interfaces on-chip, including SATA, USB, NVMe, and PCIe.

The different AM4 motherboard chipsets build additional capabilities on top of that. Here are AMD’s slides describing each, though we’ll include our own easy-to-read comparison chart later in this article.

ryzen slide AMD
am4 chipset AMD

One thing to note: All of the standard motherboard options include support for two SATA Express ports and, well, SATA Express never really got off the ground. But those lanes can easily be repurposed by motherboard makers for other uses, such as traditional SATA III ports or M.2 support, so its inclusion isn’t worthless by any means.

Here’s the plain-English breakdown of what each motherboard offers beyond what’s available in the Ryzen chip itself, starting with the entry level boards and working up from there.

A320 motherboards

asrock a320m Brad Chacos

ASRock’s A320M Pro4 motherboard, at CES 2017.

These are your basic, no-frills AM4 motherboards, intended for budget systems and (presumably) affordable big-box PCs from the likes of Dell and HP. These motherboards support a single 10Gbps USB 3.1 gen. 2 port, a pair of 5Gbps USB 3.1 gen 1 ports (augmented by the four USB 3.1 gen. 1 ports baked into Ryzen itself), and up to six USB 2.0 connections. The A320 chipset also supports a pair of SATA III and SATA Express connections, along with up to four PCIe gen. 2 lanes for additional PCIe devices, such as M.2 SSDs, third-party networking cards, and sound cards.

Crucially, while every Ryzen processor can be overclocked, A320 motherboards do not support overclocking. So if you want to squeeze more oomph out of your CPU, look elsewhere.

Only a small selection of A320 motherboards are available right now, like Gigabyte’s GA-A320M-HD2 ($70 on Amazon) and the MSI A320M Gaming Pro ($70 on Amazon). Expect to see more of these affordable offerings hit the streets this summer, as AMD’s budget-friendly Ryzen 3 processors launch on July 27.

ryzen am4 motherboard features Rob Schultz

A look at the differences between AMD’s A320, B350, and X370 AM4 motherboards.

B350 motherboards

This is definitely the sweet spot for PC gamers who stick to traditional single-GPU setups. CPU overclocking is unlocked on B350 motherboards, and compared to the bare-bones A320 boards, this chipset packs in support for an additional 10Gbps USB 3.1 port as well as two more PCIe lanes for cutting-edge SSDs like the ludicrously fast Samsung 960 Pro.

The kicker here is that multi-GPU setups are not supported by B350. I’ve seen reports of specific B350 models allowing AMD CrossFire multi-GPU configurations—but that is not something you should count on. Here’s what AMD has to say about it:

ryzen 1500x pc 15 Brad Chacos

PCWorld’s budget Ryzen gaming PC build used a Gigabyte B350 motherboard.

Only AMD’s X370 and X300 chipsets support two PCIe 3.0 x8 graphics card slots with direct access to the processor. If multi-GPU setups are used on other socket AM4 chipsets, they will not have the same PCIe 3.0 bandwidth, and those configurations are not officially supported.

You’ll find a wide variety of B350 motherboards available, including well-regarded models like the MSI Tomahawk B350 ($95 on Amazon), the Asus Prime B350 Plus ($80 on Amazon), and the Gigabyte GA-AB350 Gaming 3 ($110 on Amazon)—the latter of which starred in PCWorld’s budget Ryzen gaming build.

X370 motherboards

amd ryzen 1800x build 18 Brad Chacos

Gigabyte’s Gigabyte Aorus GA-AX370 Gaming 5 motherboard has been the bedrock of PCWorld’s high-end Ryzen test system.

Here’s where the lofty 1 percent of gamers will want to aim. Compared to B350 motherboards, the X370 platform adds four more 5Gbps USB gen. 1 ports, twice as many SATA III connections, two more PCIe lanes, and—crucially, as detailed above—dual PCIe 3.0 x8 slots able to support CrossFire and SLI multi-GPU setups.

If you want to load your PC with all the latest and greatest technologies, AMD’s X370 motherboards are the way to go. Bonus: These high-end motherboards tend to receive BIOS updates much faster than ones using the other AMD chipsets, and BIOS updates have been crucial to improving Ryzen performance while AM4 matures.

There are well over 100 X370 motherboards available, according to Newegg’s listings. These premium boards command premium prices, with a basic board like MSI’s X370 Gaming Plus costing $130 on Amazon. The $190 Gigabyte Aorus GA-AX370 Gaming 5 has been a rock-solid bed for our Ryzen system even through the platform’s early days, while fully loaded flagship boards like the Asus ROG Crosshair VI Hero and the ASRock Fatal1ty X370 Pro Gaming sell for $270.

Small-form-factor boards

asrock mini itx ryzen b350 ASRock

The ASRock AB350 Gaming-ITX/ac mini-ITX motherboard.

The AM4 socket also includes a pair of chipsets dedicated to mini-ITX small-form-factor PCs: X300 and A300/B300. These SFF chipsets don’t add any extra functionality on their own, relying instead on the capabilities integrated into Ryzen chips themselves. The major difference between X300 and A/B300? The X series focuses on gamers and enthusiasts, with dual PCIe 3.0 slots and the ability to overclock your Ryzen processor.

Oddly, we haven’t seen any motherboards based on these 300-series chipsets released since Ryzen’s launch. There are a small handful of mini-ITX Ryzen motherboards available but they rely on the traditional AM4 chipsets. The ASRock AB350 Gaming-ITX/ac ($115 on Newegg) and Gigabyte GA-AB350N-Gaming Wifi ($115 on Newegg) utilize B350, while the Biostar X370GTN ($110 on Newegg) and ASRock Fatal1ty Gaming X370 Gaming-ITX/ac ($160 on Newegg) are powered by the high-end X370 chipset. Pay attention to the hardware configurations though—these mini-ITX boards offer a reduced number of RAM and PCIe slots, among other tweaks.

Do your homework!

You still want to do your homework if you’re looking for specific features in your Ryzen PC. AMD designed the platform for flexibility, and motherboards based on the same chipset may include slightly different configurations—not to mention the usual grab-bag of extra features (such as RGB lighting, fancy audio, and one-button overclocking) tied to individual brands like Gigabyte, Asus, et cetera.

But now that you know the basics of what each AM4 chipset offers, you can quickly narrow down your search for the perfect Ryzen motherboard for you.

No matter which motherboard you choose, it should last you a nice long time. Unlike Intel, which tends to change chipsets every other CPU generation, AMD’s planning to support the AM4 platform through 2020 at the very least. 

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