B850 vs X870 Motherboards
Same AM5 socket, same processors, same memory. X870 sits a tier above B850 and the gap shows up in connectivity and lanes rather than in speed: X870 boards in our data consistently carry a PCIe 5.0 graphics slot and PCIe 5.0 M.2 storage, and a far higher share offer 40 Gbps USB4 ports on the rear. B850 covers the same basics for less.
The verdict
B850 is the sensible default for a gaming build with one graphics card. Move up to X870 if you want USB4 on the rear panel or expect to run several high-speed devices at once. Compare the actual prices below before deciding, because the tiers overlap.
What you give up, in numbers
How the two sizes actually differ once you look at every board on sale, rather than at what the standard permits. Measured across 67 B850 and 33 X870 boards at the retailers we track (65 and 33 in stock today), and updated daily.
The picks on each side
The cheapest board on each side, and the cheapest one that clears a floor worth clearing: enough power headroom for the socket’s top processor, and Wi-Fi 6E or better. Recalculated daily from live prices.
B850
X870
Best all-round
$169.99 · cheapest with the power headroom and Wi-Fi worth having
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Common questions
Is X870 better than B850?
Higher specified, not faster. Both run the same AM5 processors identically. X870 boards more consistently carry PCIe 5.0 for the graphics slot and a much higher share include 40 Gbps USB4 on the rear panel.
Do I need X870 for a gaming PC?
No. A single graphics card and an NVMe drive are comfortably within what B850 offers. X870 is worth it for the extra connectivity rather than for gaming performance.
Do B850 and X870 use the same processors?
Yes, both are AM5 and take the same Ryzen chips.
Keep going
Browse every B850 board or X870 board with filters, put two specific boards head to head, or read up on choosing a case to fit the board you pick.