Got it last week and had flashbacks of the earlier C6H days. As of BIOS 0502, I'm unable to run my Sammy B OEM modules higher than 2933MHz, no matter the timings or voltages. I was using the known stable settings from C6H to no avail. Maybe BIOS 9964 helps.
I just flashed 9964 and still couldn't post with my 3066MHz C6H settings (ProcODT 53.3), however I just got a post when using 96ohm. I wonder if the quad channel interface needs different resistances than the dual channel AM4 setup?
TR 1950X @EKWB + ASUS Zenith Extreme + 2x G.Skill F4-3200C14D-16GFX + 2x RX Vega 64 @EKWB + EIZO FS2735 + ASUS PG278Q