128GB Kit (4 x 32GB) DDR4-2400 PC4-19200 ECC Registered Memory for ASRock Rack EPYCD8-2T Board by NEMIX RAM at Amazon.com
DDR4 Memory | Registered Memory, Server RAM | ServerMonkey
Registered memory - Wikipedia
We Explain Registered and Unregistered Memory | Server Factory Explains - YouTube
CMS 6GB (3x2GB) DDR3 10600 1333MHZ ECC Non Registered DIMM Memory Ram Upgrade Compatible with HP/Compaq® Workstation Z600 DDR3 ECC UNBUFF for Server Only - B75 at Amazon.com