X570 Exposed: Up to Sixteen PCIe 4.0 Lanes, Flexible I/O

This is not the X470 replacement you were looking for, at least according to our conversations with AMD: The X570 is not a replacement for the X470, but instead slots in as a higher tier. That means the firm’s X470 will soldier on as a value-oriented alternative to high-priced X570 models, and we may even see new X470 boards with updated layouts and features targeting people who can’t justify X570 premiums.

But this “model up” philosophy provides a reason for the firm to kill PCIe 4.0 graphics support on future X470 motherboards: Anyone who wants that pathway from the CPU to the GPU will likely be forced to buy an X570 board, unless they use hacked firmware. It’s not in the firm’s interest to produce a separate AGESA for the new X470 motherboards (though we guess that this could change).

In the meantime, we spent some time over the course of several days to firm up the device connection limits for the X570 PCH.

The first thing most in-the-know readers will notice is that the PCH supports eight USB 3.2 Gen1 (5Gb/s) pathways rather than four Gen2 (10Gb/s), and then they’ll notice that it also supports eight SATA 6Gb/s ports rather than two or even four. That may seem odd since the X570 PCH is nothing more than a 14nm variant of the 12nm I/O die inside the Ryzen 3000-series processors, but it simply appears that the I/O die’s pathways are far more flexible than previously disclosed. Credit: Tom's HardwareCredit: Tom's Hardware

Moreover, a little creative destruction rids the PCH version of the CPU’s memory controller and any unnecessary appendages, as each of those maximum connections must be selectively reduced by the motherboard manufacturer to fit everything into a combined 16 High-Speed Platform Lanes. That may be just as well since device bandwidth is shared over a single PCIe 4.0 x4 connection to the CPU, though we have to at least give AMD credit for doubling that over its previous PCIe 3.0 version.

Hmm, PCH, HSIO, where have we heard that before?