ECC RAM vs Non-ECC RAM for a Celeron NAS: Non-ECC is fine for home use

ZFS checksums catch bit flips before they hit the disk, so silent corruption from non-ECC memory is more theoretical than practical for a home NAS. The error rate for modern DDR4/5 RAM is about one bit flip every few years per gigabyte, so on a Celeron NAS with 8-16GB you’d be unlucky to ever hit it. Save the money for a UPS or extra backup drive instead — that’ll protect your data more than ECC ever will.