Unbuffered ECC works fine on Threadripper — registered won't.

Unbuffered ECC (UDIMMs) is what your 1950X expects. Registered memory (RDIMMs) won’t even fit in the slots, let alone work.

Threadripper’s memory controller on Zen1 was designed for unbuffered DIMMs. ECC works as long as the board supports it and the RAM is unbuffered. Unraid doesn’t care — it just sees the corrected errors if the hardware is doing its job.

The confusion usually comes from older server platforms where “ECC” automatically meant registered (RDIMMs). On consumer TR4, it’s UDIMMs only. So grab some 3200 MHz unbuffered ECC sticks, enable it in BIOS, and you’re set.

Registered memory is for Epyc and Xeon. Different socket, different rules.