Memory syncs up with the North-Bridge, that is why anything above 3200 is kinda difficult to get stable.
I guess some CPU/MB combos where both the CPU and the MB is above average can do 3333 and even 3466,
but I guess luck is more a thing at these speeds.
I think this is a limitation by the chipset, maybe something Asus can look into but I am really not sure if it is
possible or not to unsync the two on first gen Zen or later.
DRAM Voltage on main Extreme Tweaker menu is voltage that gets applied at after memory training if I am not mistaken.
DRAM Voltage in the "External Digi+ Power Control" menu at bottom is voltage that gets applied on memory training/startup.
These two does not need to be same, but the one that gets applied on memory training/startup should not be lower.
It can be higher thou and some memory need that little extra push at start to avoid issues when pushing timings and/or speed.
Both DRAM Current Capability to 130% <-- (important on 32GB kits and up that is at or faster than DDR4-3000 and there is
no point holding back on this setting, just use 130%.) It sets a higher trip point for the DRAM channels VRM.
Both DRAM Power Phase Control to Extreme (just to test if you changed it from default, DRAM Optimized should be fine thou)
SOC voltage is kinda new for me still, and honestly is the one I am most careful with.
I do not trust the Gigabyte TR OC manual saying 1.3-1.35 is ok.
Seen some say max 1.25 is ok on some forums inclduing this one, cause same was used on X370.
I been using AUTO so I guess it is what ASUS thinks is ok for my 32GB kit and
it is close to max voltage recommended by amdmatt for Ryzen 1700X and 1800X
with high memory speeds in a post over at AMD forum.
https://community.amd.com/message/2802656?q=SOC%20voltageEven thou a 1950X is two 1800X does not mean SOC voltage should higher, if anything slightly
higher for stability on 64GB/128GB high density kits filling all 8 slots.