Had a mixed kit (2 dual-rank 16GB + a single-rank 16GB + a single-rank 8GB, different batches, only two of four carrying XMP) and no way to know the actual safe common timing without pulling sticks and testing one at a time. Nothing did this specific thing — decode-dimms doesn't read XMP, Thaiphoon Burner does great single-module reads but no cross-module math — so I wrote spd-matchtable: reads raw SPD off every installed stick, computes the worst-case timing across all of them.
Suggested starting point is always JEDEC base spec, zero OC, 1.2V — it separately shows which candidate speeds need OC-ing specific sticks and what voltage their own XMP declares, never invents a number beyond a module's own vendor data.
Also catches RDIMM/UDIMM and ECC mismatches before you waste time on timings for a kit that was never POSTing anyway.
Repo + wiki: https://github.com/apoage/spd-matchtable
well simply put it might be useful to someone ..