Well, except for what's already leaked out there or what some sites have been authorized to say so far, X570 and Ryzen 3000 series CPU's are under embargo until 7/7/19. That said, I don't have any information, or not much information that's not already out there in some form. What it looks like from the block diagrams I've seen online is that X570 incorporates some type of switching technology on the back end like Intel's HSIO that allows the motherboard vendors some flexibility that they didn't have previously for configuring their motherboard features.
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This is an example of what I'm talking about. You see where it says: "Pick one". That's for motherboard manufacturers to choose from. They can decide how they want to adjust the configuration.
So, from the CPU side nothing has changed. You get 20x PCIe lanes, 4x of which are reserved for communication with the PCH. Then you have 4x dedicated USB 10Gbps ports and dedicated storage interface comprised of four PCIe lanes. These can be allocated as a single 4x NVMe slot or it can be split into two 2x NVMe slots or it can incorporate 2x SATA ports and a single 2x NVMe slot. None of the manufacturers are likely to do anything but use this for a single 4x NVMe M.2 slot. It will almost always be a type 22110 slot.
On the PCH side, we have a dedicated 8x PCIe slot and after that the choices are in the diagram. We will probably see several variations on one pick one category and the second will probably generally be allocated as SATA ports if I had to guess. Or we'll see some PCIe switches which will allow us to have slots or an extra 2x or 4x cluster of SATA ports which will be shared. That will give us a potential for 6 to 8 SATA 6Gbps ports and the last PCIe x4 lanes that will be shared with the SATA ports will almost certainly be allocated as another x4 M.2 slot. This one, potentially supporting SATA as well as PCIe devices.
From the X570 motherboards I've seen pictures of so far, I think I'm 100% spot on with the above assuming I'm reading this correctly. The motherboards all seem to have three PCIe x16 slots. Two will be allocated as x16/0 or x8/x8 with an additional x8 slot tied to the PCH. So that's an improvement, and where all the new lanes are technically going. There are also cases where we are seeing some PCIe x1 slots scattered around the expansion slot area, so that's where one o the "pick ones" are going. The second "pick one" is definitely going towards SATA and M.2 slots. The first pick one is likely also M.2 as well. I'm seeing 3x M.2 slots on most of these boards and only one of that can go to the CPU directly.
Based on what you said in the other thread, I don't think you can get what you want out of X470 or even Z390. I think you have to decide whether or not to go with X399 or X570. No one uses PLX chips anymore because they are extremely expensive and they don't improve performance, just flexibility. The reason I bring up X399 is because it will give you what you want and there are deals to be had on Threadripper 12 core and 16 core parts. Plus, in theory, you should be able to get a drop in upgrade when Threadripper 3000 series chips hit in Q4 2019. Plus, X399 is a bargain compared to the price of some of these X570 motherboards. So that's something to think about.
