I said X390, not X399. There are two new chipsets, the X399 would obviously not be suitable if you look at the diagrams I linked to.
What i said still applies to either but fine I'll restate a bit different since i didn't note that detail.
The Soc that is RyZen puts out its own memory channels/capacity and pciex lanes and capacity, the south bridge/chipset does little to nothing of much benefit and is irrelevant in any case since whatever you have could be paired with whatever.
Neither the x390 or 399 would change the pciex and memory channels available to an r7 or lower chip so that's why I'm saying it's irrelevant any should attach to any but your only going to get more or less of each legacy port within a pciex3 x4 bandwidth budget that doesn't change, but could at the cost of user pciex lanes, a no go ish except possibly for specials like itx with multiple nvme slots for example.
. Looking at that pic is interesting though ,quad memory channels enabled by socket Am44 nice , given we know RyZen likes memory bandwidth that looks like a proper enthusiasts version of RyZen while the dual socket pic looks to be the server board layout to me.
I must not have woken up fully Mr swede I scarcely took in what i was seeing before thanks for the nudge.
I'm sold on socket 44 in that AMD said it(RyZen there start point being mainstream r7) could scale up and down a product stack and that would enable a hedt platform that can use lower binned Naples chips , i don't think they are the same socket though given the rumours, i think socket 44 is pin gate array while the server will be LGA, again smart in that it separates server and consumer parts allowing for appropriate pricing and Bom's.