First thing that I noticed about it was only one USB2 socket on the motherboard. Second, only one USB3 socket on the motherboard.
System doesn’t POST, Dr Debug says 0d… a code not listed in the manual.
Does this boards actually require both 12v rails to be populated to boot? Hopefully a new PSU arrives today to continue to solve this.
A code this low usually means the CPU is not recognised, either because it is not seated correctly, or because the BIOS does not support it.
According to the QVL the 9950X requires BIOS 20.02:
You can check the current BIOS version in the IPMI and also flash from there.
That being said, their download section doesn’t actually list BIOS 20.02, not even as a Beta. So you might want to contact AsRock Rack support, as they often give out these BIOSes if you’re willing to be a guinea pig. The QVL lists them for corporate clients for sampling.
TLDR you bought two products that the vendor says are not actually compatible with each other (yet).
While you’re at it I’d also highly recommend checking the Memory QVL since server boards are often very picky about the RAM they play nice with.
Thank you! I did update to the latest BIOS I could find. I will contact support next.
did they provide you creds to access it?
yes they did 
I can’t wait until the weekend to get back to this build
do you mind sharing it in DM? would appreciate. in my case they don’t reply for two weeks
I updated to BMC firmware 5.03, then I reset my login password and upgraded BIOS to 20.05.
Hardware detection …indeterminate…but Dr Debug is at 0x15…,
Remote console shows BXE…
and it reboots to the EFI shell. Definitely progress!
when I go into Advanced → H/W Monitor, this gives me a progress bar and updates all the I2C readings as they are detected!
I’m glowing with joy with that
This is new to me! We have twice the number of pre-fetch features here
curious about Local APIC mode x2 mode. A bunch of AsrockRack mobos will zork out if you select x2APIC instead of Auto
Here’s a setting I havent seen yet: LUL
Latency Under Load : Enabling may improve latency in heavy BW scenarios. May slightly reduce peak CCD BW
OK, here’s an area where I typically have to disable PXE (etc) to speed up boot time, but it’s now disabled by default:
Not tinkering with these setting until after I get an OS installed.
IPMI screen jumps to 1920x1080 no problem. Glad I have a 4K monitor
ok, I don’t know why enp4s0 is not connected but likely my cable is plugged into the IPMI port and that reports as enx8mumble
this is GREAT and I’m very happy and confident that this build is going go well.
Next, I’m going to order some ECC ram 
enx links have MAC-address based naming. And yeah, it’s just an IPMI port in my case, but I cannot get it working for the internet for some reason.
