AMD X570 Ryzen 3000 Zen 2 Chipset Block Diagram Revealed With 24 PCIe 4.0 Lanes

AMD Motherboards
We are exactly one week away from the start of Computex 2019, and barring a surprise change of plans, AMD will announce its new generation Ryzen 3000 series of desktop processors based on its Zen 2 CPU architecture. AMD is also expected to unveil its X570 chipset. Ahead of the event, a block diagram has emerged showing the PCie makeup of the upcoming chipset.

To be clear, existing owners of X470, B450, X370, and B350 motherboards will in most cases just need a BIOS update to support the upcoming crop of processors—AMD is retaining support for its AM4 socket. That may or may not be the case for budget-oriented A320 and A300 motherboards (whenever we inquire about that, motherboard makers typically tell us they have nothing to announce at this time, in regards to BIOS updates for A320 and A300).

Even though a new motherboard will not be required in most cases, one thing the X570 chipset will introduce is PCI Express 4.0 support. That equates to more bandwidth to feed multiple graphics cards or, perhaps more useful for most users, multiple NVMe solid state drives. Here's a look at a block diagram that shows the arrangement of the lanes...

X570 Block Diagram
Image Source: Guru3d via Chiphell

Standard disclaimer applies—this is not an official document that we are aware of, so take the information with a grain of salt. That said, the diagram is at the very least a plausible design.

Looking at the diagram, we see the CPU serving up 24 PCIe 4.0 lanes, with 16 of them jettisoned to two PCIe x16 slots for graphics cards. Those slots can be configured as either PCIe 4.0 x16 or x8/x8.

For storage, the diagram indicates that four PCIe 4.0 lanes go to 32Gb/s M.2 slots. That leaves four remaining PCIe 4.0 lanes, and those are used to connect the CPU to the X570 chipset, which itself handles traffic for things like USB 3.1 Gen 2 connectivity, Wi-Fi and Bluetooth, SATA 6Gbps, and so forth.

In terms of transfer speed, here's how it scales with each PCIe standard...
  • PCIe 1.0: 2.5GT/s
  • PCIe 2.0: 5GT/s
  • PCIe 3.0: 8GT/s
  • PCIe 4.0: 16GT/s
The bandwidth varies by configuration, but looking at the top end, PCIe 4.0 x16 delivers around 31.5GB/s of bandwidth, which is double that of PCIe 3.0 x16 (15.75GB/s).

There has also been talk of X470 and B450 motherboards supporting PCIe 4.0 when paired with a Zen 2 CPU (and with a BIOS update). We will have to wait and see if that is true.

While we wait for final word on all of this stuff, motherboard makers have started doling out BIOS updates for existing socket AM4 models, and have been teasing upcoming X570 product launches. From what we can tell, the usual suspects (ASUS, ASRock, Biostar, Gigabyte, MSI, and others) are ready to go with new X570 boards, it's just a matter of waiting for AMD's official launch.