B840 is the entry-level 800-series AM5 chipset. The graphics slot and M.2 storage run at PCIe 4.0 at most, the chipset's own lanes are PCIe 3.0, and only memory overclocking is supported, not CPU overclocking. It suits a plain Ryzen build where the board simply has to work; B850 is the better buy if you want PCIe 5.0 storage or plan to tune the processor.
Guide:AMD B840 chipset guide — AMD B840 is the entry AM5 chipset: PCIe 4.0 at most, chipset lanes at PCIe 3.0, memory overclocking only, no CPU…
17 B840 motherboards tracked · from £84.99 · 3 with a Warehouse offer · showing 1–17