Quick edit for future people: A bios update a month or 2 ago roughly, has made the ram situation a lot better. I now have memory context restore off, and I can boot with its stock speeds. Training is also now not completely unreasonable (less than a minute it feels), and I no longer worry about if it will or won't turn on.
This is not tech support, nor a build question, nor overclocking, so this seemed the most appropriate place to make a post regarding how a hardware match up worked out.
I purchased the Asus ProArt X870E-Creator WiFi due to its unique combination of ECC support, its PCIE layout and its integrated 10gbe and 2.5gbe NICs.
Regarding ECC, this board has some ECC modules in the QVL (All 4800 and limited to 64 gigs), but I wanted 96 gigs, in 2 UDIMMS.
I purchased 2 Kingston KSM56E46BD8KM-48HM ECC UDIMMS with the ProArt X870E-Creator WiFi. These are 2 48GB dual rank 5600 sticks with multi-bit ECC.
This configuration has difficulty booting at the stock 5600 speeds, endlessly stuck in memory training (I assume) and unable to post/get to the bios. This is somewhat disappointing, but I am able to get it to boot reliably in a typical, short amount of time with 5400 MT/S and with "Memory Context Restore" enabled.
I really hope future bios updates allow me to run it at the stock speeds that should be supported by my CPU (9950X), but for now this does work, and so I just wanted to post this in case someone else was curious about a similar setup and wanted to know if it would work.
Will it work? Yes, but you want to turn on memory context restore, and might have to lower your MT/s to 5400 and of course enable ECC (All bios settings).
If you are a future user who happens across this, purchases a similar setup, and are able to boot at stock JEDEC speeds with a bios update I would appreciate a ping letting me know that it worked.
Memory Information
This is memory information from running
dmidecode -t memory
Below, the 72-Bit total bus width and error information handle are indicators that ECC is recognized/working
Memory Device
Array Handle: 0x0013
Error Information Handle: 0x0017
Total Width: 72 bits
Data Width: 64 bits
Size: 48 GB
Form Factor: DIMM
Set: None
Locator: DIMM 1
Bank Locator: P0 CHANNEL A
Type: DDR5
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 5600 MT/s
Manufacturer: Kingston
Asset Tag: Not Specified
Part Number: 9965794-036.A00G
Rank: 2
Configured Memory Speed: 5400 MT/s
Minimum Voltage: 1.1 V
Maximum Voltage: 1.1 V
Configured Voltage: 1.1 V
Memory Technology: DRAM
Memory Operating Mode Capability: Volatile memory
Firmware Version: Unknown
Module Manufacturer ID: Bank 2, Hex 0x98
Module Product ID: Unknown
Memory Subsystem Controller Manufacturer ID: Unknown
Memory Subsystem Controller Product ID: Unknown
Non-Volatile Size: None
Volatile Size: 48 GB
Cache Size: None
Logical Size: None
