AMD’s 800-series is divided into four distinct chipsets for different market segments and use cases. It’s not as obtuse as the 600-series but there are still nuances to account for, thus ensuring that a system isn’t needlessly overspecced.
Members of the 800-series are built around the AM5 socket platform and support Ryzen 7000 and 9000 CPUs as well as 8000-series APUs. PCIe 5.0 lane allocation and supplementary I/O are the main factors delineating the four 800-series chipsets.
X870E is the full-fat configuration that utilises two Platform Controller Hubs (PCHs) in concert for the platform ‘chipset’. It offers up-to 16 PCIe 5.0 lanes for the GPU (or, optionally, a 2x8 mode), four for the primary M.2 slot, and the final four reserved for the communication link between CPU and chipset. From the chipset an additional 20 general purpose PCIe lanes are available, putting the total (off-CPU + off-chipset) to 44.
X870 ‘non-E’ meanwhile still offers the same config PCIe 5.0 options for GPU and primary M.2, but fewer PCIe lanes are offered off-chipset due to having only one PCH.
As a dual-PCH chipset, X870E has the full gamut of platform I/O capabilities including two USB4 40Gbps ports, USB 3.2 Gen2x2 ports and as many as 8 SATA ports. The single-PCH X870 has up-to exactly half available in its base configuration, which nonetheless will still be plenty for most users. Motherboard manufacturers may offer additional I/O capabilities through auxiliary on-board controllers.
So, X870 if you really want PCIe 5.0 graphics and NVMe SSD support, X870E if you also want additional I/O options at a higher price. All X870 and X870E-series motherboards should support WiFi 7 (802.11be) as standard too.
B850 motherboards will be available at a later date and take the platform capabilities down a step. PCIe 5.0 graphics are now optional but PCIe Gen5 NVMe SSD support is still assured. The exact makeup of advanced I/O is yet to be confirmed but we hope that both USB4 and WiFi 7 are regularly present on these designs.
There is no ‘E’ variant of the B850, eliminating a repeat of the somewhat muddled 600-series lineup caused by the presence of the B650E chipset. That also means there will be no ‘affordable’ 800-series variants with the full range of I/O options for those who don’t need PCIe 5.0 GPU support.
B850 series motherboards will be stiff competition for X870 once released, particularly if their de facto PCIe 5.0 support extend beyond just M.2 NVMe storage. Until then X870’s main competition are more affordable X870E boards and older 600-series designs.
B840 meanwhile is a cut-down budget board analogous to the older A-series design with support for only PCIe 3.0 graphics and NVMe SSD. It should generally be avoided except in very specific circumstances and will typically be a chipset exploited by OEMs and cheap System Integrator options.
We would be remiss to not mention that the old Curve Optimiser tool, which allowed Ryzen 7000-series processors to undervolt the CPU in a manner that was PMFW/PBO aware, has been depreciated. Instead, the 9000-series CPUs have access to a ‘Curve Shaper’ tool on 800-series motherboards to assign voltage margins in up-to 15 different frequency-temperature bands, allowing for finer control for voltage adjustment in bands that are stable and usable. Curve Shaper tables apply across all cores, and can also be shifted as a group by Curve Optimiser.
