What this checker decides
“ECC support” is not one yes-or-no specification. A useful purchase decision needs the exact CPU, the exact motherboard and any named revision, a board-vendor statement about ECC UDIMMs, firmware evidence, and an exact memory-module check. Corrected-error reporting in the deployed operating system is a further verification step.
This first catalog covers ASUS PRIME X670E-PRO WIFI, ASRock Rack B650D4U, and GIGABYTE MC13-LE0 revisions 1.x/3.x/4.x, paired with either the AMD Ryzen 9 9950X or AMD Ryzen 7 8700G. It gives a concrete outcome only at the level the sources support: an exact documented path, incomplete evidence that names the missing check, or a configuration the board vendor does not document.
ECC UDIMM is different from DDR5 on-die ECC
DDR5 includes correction inside each DRAM component. That on-die function does not establish the end-to-end ECC UDIMM path between the memory module, CPU memory controller, motherboard, and firmware. The board and CPU selection above is about ECC UDIMMs, not the baseline on-die feature present in DDR5 generally.
How to use the result
An exact documented path means the board vendor supplied an exact CPU row with ECC DIMM support. Incomplete evidence means board-level ECC and CPU-family evidence align but an exact board/CPU row, firmware version, or module confirmation is missing; the result names the vendor check to make before buying. Not documented is a stop sign for assuming support; it does not claim the hardware is physically incapable.
Even a documented result is not an injected-error test. Match the exact memory part number to the current vendor QVL, confirm firmware for the exact CPU and board revision, check that ECC is enabled, and verify how the deployed operating system reports corrected and uncorrected errors.