[otakucode]

The difference is that NAND doesn't need to BE high density except in those mobile devices. For both consumer grade SSDs and enterprise SSDs, NAND already has such a huge storage density advantage that if they actually used up the space available inside a 2.5" or 3.5" case and weren't concentrating on transfer speed as much, yields wouldn't be much of a problem.

NAND does actually have a degree of flaws it can tolerate as they are made today in consumer SSDs. I am not certain, but SLC Enterprise SSDs made for database servers and the like might get the best yield chips I'd guess. On consumer grade devices, there is an amount of 'slack' space that the chips actually can accomodate that is used for relocating data from damaged areas, wear levelling, some bookkeeping, etc. So if you buy a 1TB SSD, there might be enough actual storage on the chips to hold 1.1TB if all of it was made available. I'd not be surprised if particularly bad runs come out and get binned as 512GB devices because large portions of the chips are unreliable.

[warrenm]

This is not especially dissimilar from how CPUs were made and marketed for years - CPUs that wouldn't clock at 1.6GHz would get sold as 1.4GHz, for example

Kinda like how ladders are rated: they say 300Lbs .. it'll probably take more than double that - but if it breaks when you overload it, the manufacturer can point to the rating and say, "you exceeded its spec"