even back in the DDR3 days; esp for 2Gbit BFR/CFR and 4Gbit MFR (likehereorhere). The older datasheets did not even have the "M-die" type of naming anywhere in them, just the full IC name.
Even if Gen3 vs Gen4 NVME isn’t night-and-day in real life, a faster boot time by even a second is something you notice! Now I’ve gone from Gen3 to Gen4 NVME, DDR4 to DDR5, and a CPU that’s clocking an extra 600-700MHz more than my last one – so where’s that tiny...