When selecting a motherboard for your newly purchased Ryzen CPU, you will encounter four main options: X670, B650, A620, and the newest addition, X870. But what do these names mean? How do X870E, X670E and B650E boards differ from their non-E counterparts? Which should you choose for your system? This guide will provide all the answers and more.
The biggest difference between motherboard types is the chipset – the chip (or two chips) that connects the CPU to other components in the system. In the past, the chipset consisted of a northbridge chip, which connected the CPU to the RAM and graphics card, and a southbridge chip, which connected the northbridge to the rest of the components. Nowadays, however, the functionality formerly attributed to the northbridge is integrated into the CPU, which connects directly to many components.
Ryzen 7000 and 9000 processors connect to high-bandwidth components through 28 PCIe lanes and support PCIe 5.0 speeds. Of these lanes, 16 are reserved for a graphics card (or two, with each utilizing eight lanes), and four are designated for an M.2 drive. Another four lanes are used to connect to the chipset. The remaining four lanes can be employed for elements such as another M.2 slot or a USB4 adapter that also connects to the CPU’s integrated graphics to enable DisplayPort tunneling.
Ryzen 8000G processors only have eight PCIe lanes for a graphics card (20 in total), and support PCIe 4.0 speeds. Additionally, Ryzen CPUs support four USB 3.1 (or “3.2 Gen 2”) ports and a single USB 2.0 connector.
All current chipsets on the AM5 platform support only PCIe 4.0 speeds, which limits the total bandwidth of the devices connected to them at approximately 7GB/s. These devices may comprise storage drives utilizing either the NVMe or SATA interface, USB devices, network cards, and other internal components such as soundcards.
Some motherboards feature more connectors than their CPU and chipset support, either to allow you to choose between some of them or because they employ splitters to share their bandwidth.
With the basics covered, let’s move on to the chipsets themselves…
A Needless Compromise: A620
A620 motherboards use the same Promontory 21 chip used in B650 and X870 motherboards, but with some of its connectors disabled or limited. It adds support for two USB 3.1, two USB 3.0 (or “3.2 Gen 1”), and six USB 2.0 ports. It also incorporates eight PCIe 3.0 lanes, of which two or four can be employed for SATA ports.
The real issue with A620 motherboards isn’t the chipset itself; rather, it’s that they are designed to be affordable boards with inexpensive voltage regulator modules (VRM) and do not support PCIe 5.0 speeds. They also only support a single graphics card, though the era of multi-GPU gaming has essentially come to an end so that’s not a big one.
Finally, A620 motherboards not only disallow CPU overclocking, but they may also officially support CPUs with a TDP of up to only 120W, or even 65W.
On paper, A620 motherboards are a good fit for Ryzen 8000G processors, which are meant for compact systems with fewer components and lower power consumption. In practice, decent A620 boards cost about the same as B650 ones, so we can only recommend them when they are on sale.
The Best Value: X870 vs. B650E vs. B650
B650, B650E and X870 motherboards all use a single, fully enabled Promontory 21 chip. It adds eight PCIe 4.0 lanes, allowing an M.2 drive to fully utilize the chipset’s bandwidth on its own. Like the A620, it also includes four PCIe 3.0 lanes that can be used for up to four SATA ports.
The chipset provides support for six USB 2.0 and four USB 3.1 ports, as well as bandwidth that can be allocated for an additional two USB 3.1 ports or a single USB 3.2 (“Gen 2 x 2”).
Read our review: Most Affordable AMD B650 Boards Tested
If you were wondering about the difference between B650 and B650E motherboards, the answer is that B650E boards (E = short for “Extreme”) support PCIe 5.0 for both the graphics card and at least one M.2 drive. X870 motherboards are basically the same as B650E, except they are required to use four PCIe lanes for USB4. However, because they are newer, the Wi-Fi cards they come with support Wi-Fi 7 rather than 6E.
Regular B650 boards may still have a PCIe 5.0 M.2 slot. Other than that, these boards don’t limit the CPU in any way and will support any Ryzen processor until 2027.
We recommend B650, B650E and X870 motherboards for gamers and others who want to get everything that AM5 motherboards have to offer, but don’t need to connect many drives to their PC simultaneously. Another advantage of these boards is their ability to fit all connectors into a compact micro-ATX form factor, which is useful if you’re seeking a compact case to place on your desk.
More is More: X870E vs. X670E vs. X670
X670, X670E and X870E motherboards feature a Promontory 21 chip connected to another one through four PCIe 4.0 lanes, providing the second chip with the same bandwidth as the one connected to the CPU.
Combined, the chipset adds twelve PCIe 4.0 lanes, allowing each M.2 drive to saturate the chipset’s bandwidth individually, and eight PCIe 3.0 lanes for up to eight SATA ports. With SATA now becoming a legacy connector, it’s common for some of those lanes to be allocated to network cards, freeing up all PCIe 4.0 lanes for faster interfaces.
The chipset also offers support for twelve USB 2.0 ports and one of three options: twelve USB 3.1 ports; ten USB 3.1 ports and one USB 3.2 port, or eight USB 3.1 ports and two USB 3.2 ports.
Read our review: The Best AMD X670E Motherboards: 22 Board Roundup
Unlike B650, all X670 motherboards feature a PCIe 5.0 M.2 slot, and of course, X670E boards support PCIe 5.0 graphics cards. If you purchase such a card when they become available, it probably won’t even require all 16 lanes. So, if your board has another 16-lane PCIe 5.0 slot, you’ll be able to use it for up to two M.2 drives with an adapter (some boards actually come with one). With X870E you can be sure you’ll get USB4 and Wi-Fi 7.
X670, X670E and X870E motherboards are the ideal choice for content creators who constantly feel the need to add another drive to their system. With numerous ways to utilize the dual chipset, particularly, you shouldn’t buy a motherboard based solely on its name; instead, make sure it has all the connectors you require.