F4-4000C18D-64GTZR timings and voltage at lower speeds?

[ezakimak]

The packaging and XMP profile says 4000 18-22-22-42 @ 1.40V.
So, one would think it should run slower at the same or lower voltage. However, it won't even run at 3600 18-22-22-42 at less than 1.44V --it needs even higher voltage!
How could this ram have ever run at 4000 @ 1.40V ?

Thaiphoon burner can't tell what die it's using, only that it's Hynix. Does anyone know?

[emissary42]

Out of the different Hynix 16Gbit ICs probably one of the single die variants. The last letter of the lot code above the barcode on the label, tells you the actual die revision.

[GSKILL TECH]

What motherboard and CPU do you have? Are you using the latest BIOS? It may not be the DRAM Voltage that is the limiting factor.

[ezakimak]

The last letter of the lot code is M. What does that mean?
ASRock X570 Taichi, latest bios.
Ryzen 9 5950X

[emissary42]

Hynix 16Gbit MJR (H5ANAG6NMJR).