Sorry hard to find out what is b-die or not.
That's the issue with memory in general, it's hard to find out who made it, what revision it is and what quality it is. If it's not in QVL (of either board maker or memory maker), it's just lottery based on assumptions (and what you can google of it).
So I can't give any concrete suggestions.
1. I know all motherboards are good for TR4, but you said Zenith has best ram compatibility. I don't need the Gigabit connection, is Zenith II extreme the best choice in that case?
2. Am I making some noticable sacrifice going to 256 GB ram? I think I can live with 128 GB, but if I can go 256 without sacrificing anything, I'd rather do that.
3. Anything better that the 970 EVO plus? I don't want to do raid as I had a bad experience before, so looking for the fastest out of the box.
4. No idea on how to choose a power supply, but the price difference is so small I figured I'd go with the "best" any one in particular you can recomend?
1. It seems to be the case based from reviews done so far and the fact memory vendors like G.Skill provide QVL for this board for almost all their kits.
2. No sacrifice at all, in fact, opposite. 32GB DIMMs are effectively quad-rank which improves performance despite slightly worse clocks&timings. High-core CPUs also benefit from more memory. 3990X & 256GB is fantastic match, I am waiting for such kit as well.
3. Depends on what you would consider to be better, 970 EVO is mainstream mid-market budget option. For system drive, random low queue depth 4K access and latency are only things that improve performance but I don't think you would notice. I am not sure I can tell any difference with my Optane drive, and there is nothing better in world :- ). 970 EVO 2TB is still great choice, I personally would trust it little bit more than PCI 4.0 drives from less reputable brands like Sabrent, but it doesn't matter as long as you have good back-up.
RAID 0 is in my opinion rather worthless and unwise for SSDs, it improves already gigantic sequential speeds which don't matter at all for system drive, and worsens latency which does matter. And of course,.. helps you loose your data easier, esp. with consumer drives that don't offer any power-loss safety.
RAID 1 improves read speeds somewhat, but you're wasting expensive drive to do so.
4. High-end all-digital platforms like PRIME is the best you can get regardless of efficiency rating. The only better PSU than these is Corsair AXi 1600 (
Only this one, not any other wattage) which is adequately obscene priced :- ).
Right now no one else has anything comparable to offer, the ultra high-end options from EVGA and SUPERFLOWER, both excellent vendors are older designs. BeQuite showed Dark Power Pro 12 at CES but with current situation, I don't even think it will come this year.
This is going to be one hell of a machine!