Features of the chipsets for the Ryzen 7000 revealed: the older X670 is made from two average B650s

The day before yesterday at the opening of Computex 2022, AMD unveiled the Ryzen 7000 family of desktop CPUs and the 600-series chipsets for them.
As it turns out, these chipsets are being developed by ASMedia, and their design uses a modularity similar to the chipset approach to processor design.AMD has announced the existence of three chipsets for future Ryzen 7000 series desktop CPUs: the ultimative X670E, the flagship X670 and the mass-produced B650.
The first two chipsets on this list are the same solution with purely marketing differences.
Boards based on X670E will be richer and allow the installation of two graphics cards simultaneously, and in the X670-motherboard AMD will prohibit bifurcation bus PCIe x16 for graphics gas pedals, and allow not to implement PCIe 5.0 support.Angstronomics website shared the details of what features will be inherent in chipsets for Socket AM5 platform.
The source reports that this time AMD has completely shifted the burden of chipset creation, and X670 together with B650 was developed by ASMedia.
This allowed them to implement an interesting scheme: both chipsets use the same chip with code name Prom21, but X670 uses two such chips at once.
In fact it means that X670 has twice as many ports and lanes of PCIe than B650.
B650 chipset consists of one basic chip Prom21, it supports PCIe 4.0 x4 bus for connection to CPU and eight PCIe 4.0 lanes for peripherals and expansion slots.
It also comes with four PCIe 3.0 lanes, reconfigurable SATA ports, six USB 3.2 Gen2 ports (pairable to USB 3.2 Gen2×2 with bandwidth up to 20Gbps) and six USB 2.0 ports.
The X670 chipset combines two of these chips, which are connected to the processor and to each other in series with the PCIe 4.0 x4 bus.
This means that a \"swag\" of two Prom21 chips will be able to offer 12 PCIe 4.0 lanes, 8 PCIe 3.0 lanes (some of which are converted into SATA ports), 12 USB 3.2 Gen2 ports and 12 USB 2.0 ports.
Added to this functionality in both cases are the SoC capabilities of the Ryzen 7000 processors themselves.
In addition to 20 PCIe 5.0 lines for graphics and storage they support PCIe 4.0 x4 interface for chipset, PCIe 4.0 x4 interface for external USB 4.0 controller, two USB 3.2 Gen 2 ports and two USB 2.0 ports.
As the source notes, using modularity to build chipsets solves several problems.
Firstly, it unifies and flattens their design, which facilitates development and reduces the cost of production.
Secondly, motherboard manufacturers are able to reduce the length of signal lines, which can be a critical factor in the implementation of high-speed ports.
Thirdly, the problem of heat dissipation is solved.
The thermal package of one Prom21 chip is 7 Watts and X670 boards with two chips set away from each other can easily do with passive cooling which would be difficult to achieve if all options of this logic set were realized in one chip.
It will be released a few months after the first representatives of the Ryzen 7000 series and will be based on the same Prom21 chip.
But it is supposed to have reduced number of PCIe 4.0 lanes to 4.
Expect to see Ryzen 7000 processors on Zen 4 architecture and motherboards with Socket AM5 processor socket and DDR5 memory support coming to market this fall.