In their briefing leading up to today's Ryzen 3 3100 and 3300X review embargo, AMD disclosed that its upcoming "Zen 3" 4th generation Ryzen desktop processors will only support AMD 500-series (or later) chipsets. The next-gen processors will not work with older 400-series or 300-series chipsets. This comes as a blow to those who bought premium X470 motherboards hoping for latest CPU compatibility running into 2020. At this time only B550 is available, but we expect more news on enthusiast chipsets as the Zen 3 launch date comes closer. AMD B550 is a fascinating new mid-range chipset by AMD. Launching today as a successor to the popular B450 chipset, B550 is a low-power silicon with roughly the same 5-7 W TDP as the older 400-series chipset. Although AMD won't confirm it, it's likely that the chipset is sourced from ASMedia. It brings a lot to the table that could draw buyers away from B450, but it also takes some away.
The AMD B550 currently only supports 3rd generation Ryzen "Matisse" processors. Ryzen 3000 "Picasso" APU are not supported. What's more, older Ryzen 2000 "Pinnacle Ridge," "Raven Ridge," and first gen Ryzen 1000 "Summit Ridge" aren't supported, either. The Athlon 200 and 3000 "Zen" based chips miss out, too. AMD argues that it ran into ROM size limitations when trying to cram AGESA microcode for all the older processors. We find that hard to believe because B450 motherboards with the latest ComboAM4 AGESA support 2nd gen and 3rd gen processors, including APUs and Athlon SKUs based on the two. On the bright side, AMD assured us (within its marketing slides for the B550), that the chipset will support upcoming processors based on the "Zen 3" microarchitecture. The company also came up with a new motherboard packaging label that clarifies that the processors won't work with the 3400G and 3200G.