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MSI's $80 AMD motherboards with DDR4 support swoop in to rescue gamers amid the global RAM crisis
(www.tomshardware.com)
This is a most excellent place for technology news and articles.
Not sure if the AI side is any different, but all the data and compute servers I've built used DDR DIMMs, only they needed to be ECC to even POST.
If it was server hardware they probably needed more than just ECC. They were probably RDIMM or LRDIMM which have built in registers to handle addressing larger amounts of memory.