I have a new system with an AMD 3900X. The performance is much better than with my old Intel - which is obviously no surprise since it was an old cpu. There were some surprises though, one is that it did lower my cpu usage significantly (by maybe 20%) when I turned off hyperthreading (SMT or how AMD calls it). So now I’m using 12 real cores instead of 24 hyperthreaded ones. ASIO guard is on here. The other one was that my UAD Quad card didn’t work with my motherboard / CPU combo - so I had to buy a UAD Octo on top to be able to use my UAD plugins. I spent more money on that than on the whole new Computer. Despite some intensive research before I made my hardware choice I hadn’t found anything about that potential problem on the web.
So, to answer your question whether your new computer will be compatible with cubase - from my experience: yes, it will. It will be a great system. I am not sure if the 3950X will have significantly more performance than the 3900X. Yet in my case, when I see my task manager, I can’t shake the feeling that it only uses 30% of the possible performance, but I guess I am overlooking some bottlenecks.
Michael