Re: Diminishing Returns
DougS, "Fractional bits...mean even tinier increases..."
No. Not necessarily. It might mean the opposite.
Fractional bits means being able to optimise the voltage steps, and then accepting as many bits (including fractional bits) as can be represented by that number of voltage steps. Fractional bits (per cell, like 3.7 or 4.3 bits per cell) is another way of saying some bits are effectively spread over several cells. Requires circuits to extract and recombine, raw data (as distinct from error correction).
They're saying that "QLC" are now more feasible with the additional of error checking, which is certainly a "Well duh" invention. Quad (4) "Level" (sic) Cells implies 16 voltage *levels*, representing Quad (4) *BIT* Cells. The next mindless step would be "5LC" (sic), which implies 32 voltage levels. But that assumption is dumb, and traceable to the dumb nomenclature which implies power of two voltage steps.
My basic point is that there's no reason to assume that the optimum number of voltage levels is going to be 8, 16, and 32. It might be 10, or 17, or 23. The optimum number of voltage levels will change over time (with progress) and (of course) is related to other design decisions.
If you're not following, then re-read all my posts on this topic.
PS: This concept of fraction bits is very basic and as old as the hills. I'm not suggesting anything new, I'm just here to grumble about the daft nomenclaturism, e.g. "TLC" (sic), and to hopefully correct the thinking of anyone so affected.