Is there concrete information regarding how many PCI-E lanes the CPU has, and how many the various chipsets have?
As
@bean pointed out there are 24 PCI-e 3.0 lanes from the processor. 16 lanes for the GPU, 4 lanes to the chipset, and 4 lanes for either an M.2, split between and M.2 and SATA, or split between SATA and general purpose use. There are also 4 USB 3.1 Gen 1 (formerly 3.0) ports directly from the processor.
As for the chipset, you get (what a lot of people miss) either 4 general purpose PCI-e 3.0 lanes or 2 SATA Express ports, 8, 6, or 4 PCI-e 2.0 lanes, 4 or 2 SATA III ports, and a combination of USB depending on the chipset.
I am not sure the Dual PCI-e Slots for X300 in the chart above is accurate. I'm also curious about how the RAID is handled.
What will be interesting to see is if x300 chipset changes that around as the chipset doesn't do much.
By the above chart, I had assumed the X300 would be very minimal, simply flowing the 4 PCI-e 3.0 lanes through, possibly providing a SATA alternative. Motherboard manufactures could then route a lane to gigabit ethernet, a WiFi card, and have USB and/or SATA bridges on the other two lanes.
However, Guru3D showed
a chart with I/O for the X300 that sourced
ComputerBase, but I am highly skeptical of it: it has "0" for the number of PCI-e lanes on X370, B350, and A320.
I'm not too concerned about CPU performance this time around - the leaks seem to all collaborate that performance will be what AMD is stating. What concerns me is the reliability of the chipset drivers/software, if ECC is supported, and the lanes and configurations.
For ECC, you will probably have to wait for the "Pro" processors. I am not aware of any reason the new chipsets will or won't support it...they're supposed to be pretty universal, but they haven't been talked about much by AMD yet. Supposedly the BIOS' are still being refined, so the good news is that getting better performance from this new platform may simply be a BIOS flash down the road.