Flash memory is uniform. Every flash memory die is (hopefully) identical to the next one. Once you know how to produce a flash memory die of a given size, you can produce a million of them, and that's worth a million times more.

Chia plots are unique. Producing two copies of one isn't just pointless, but undesirable; it means that someone else might get a copy and reap the rewards instead of the person who plotted it.

The idea is you plot into a one time programmable thing either at the factory or on first use (so single die, multiple values).

That said it needs to be cheaper than HD, as the SSD is apparently only used to build the plot, so maybe impractical indeed.

Curious that the plotting hasn't already moved to DRAM, apparently 256GB is needed to build a plot which is not too wild on server-class computers.

> The idea is you plot into a one time programmable thing

... like flash memory?

Flash storage has been heavily optimized. You're not going to do any better than that with custom silicon.

> Curious that the plotting hasn't already moved to DRAM, apparently 256GB is needed to build a plot which is not too wild on server-class computers.

My understanding is that people have done the math, and using an SSD ends up being cheaper, even considering the fact that it'll wear out prematurely. (And, in the case of hosting services like Scaleway, the miner isn't concerned -- their hosting provider is the one burdened by this usage.)