Back in 2016, AMD made a commitment or rather a promise to continue support for AM4 socket until 2020, and it has gone quite a way. According to AMD, the company has increased the core and thread count on the same socket by 4x and 8x, respectively (4C4t to 16C32t). The socket has gone through four architectures, Excavator, Zen, Zen+, and Zen 2, across four different manufacturing processes, 28nm, 14nm, 12nm, and 7nm. It has also brought 33 percent higher DRAM bandwidth, from DDR4-2400 to DDR4-3200+, and four times higher PCIe bandwidth, from 12x PCIe Gen3 to 24x PCIe Gen 4.
AMD will support Zen 3 with AM4 socket, but only on B550 and X570 motherboards
The big part of the news is that AMD will support future Zen 3 CPUs on its AM4 socket, but only on B550 and X570 chipset motherboards. The Ryzen 3000 series processors are supported on X470, B450, X570 and B550 motherboards, while AMD Ryzen 3000 Series with Radeon Graphics (APUs) don't have support on B550 chipset motherboards. The same goes for older AMD Ryzen 2000 series CPUs.
As you can see from the table above, the older AMD Ryzen 2000 series processors with Radeon Graphics, or APUs, end with B450, and the same goes for Ryzen 1000 series CPUs and Athlon with Radeon Graphics APUs.
In the blog post, AMD' Robert Hallock, Technical Marketing lead for AMD consumer processors, also said that there are no details on how long will the same socket AM4 last from here, as it depends on the schedule of industry I/O technologies, which typically require adjustments to the pin count or layout of a processor package.
The B550 chipset brings PCIe Gen 4, and USB 3.2
The AMD B550 chipset brings a lot to the table and takes some from the B450 and some from the high-end X570 chipset. It will have support for PCIe Gen 4 x16 on the CPU graphics side, and PCIe Gen 4 for CPU storage support, just like the X570 chipset. This means that the main PCIe x16 slot and one of the M.2 NVMe slots are PCIe Gen 4. It also supports dual graphics, if someone wants to use it.
There is also USB 3.2 Gen2 support, just like on the X570 chipset, with support for 4x SuperSpeed on 3rd gen Ryzen 3 CPUs.
On the other hand, all "general purpose lanes" are PCIe Gen 3, which includes CPU chipset uplink, which is a mixed upgrade from the B450, which had PCIe Gen 2 general purpose lanes and PCIe Gen 3 CPU chipset uplink. Bear in mind that the X570 chipset uses PCIe Gen 4 for both general purpose lanes and CPU chipset uplink.
In total, the B550 chipset comes with 16x graphics PCIe Gen4 lanes, 8x general purpose PCIe Gen 4 lanes, 6x SuperSpeed USB 10Gbps ports, 2x SuperSpeed USB 5Gbps ports, and 6x Hi-Speed USB 480Mbps ports, which are fixed. There are also optional, or 10x flexible PCIe Gen 3 lanes, which can be used in several configurations, depending on the motherboard manufacturer, and set to 2x4 NVMe and 2x SATA 6Gbps, 1x4 NVMe and 6x SATA 6Gbps, or 2x4 NVMe and controllers.
There are also four SATA 6Gbps ports, and one 4x PCIe Gen uplink to CPU.
Coming on June 16th, starting at $100
According to AMD, there are over 60 motherboard designs in development from Asus, Asrock, Biostar, Gigabyte, MSI, and others, and AMD says motherboards are coming on June 16th, with pricing starting at $100.