Was thinking about a 3900x, but in the long run i think i'm just tempted to upgrade for the sake of something new. I have 3600mhz ram that my 2700x absolutely hates and i generally keep it around 3000mhz. A 3900x is more likely to run it at max speeds i suppose but not sure what that would do for performance, barely noticable gains im guessing?
Some with a ryzwn system will come along to answer you soon, but from the tonnes of information ive read and watched, getting your memory at 3600mhz and IF you will get a good chunk of performance extra.