To answer the original post: on an SSD the locations of each piece of data are not fixed. The SSD itself maintains a mapping of where things are stored, to avoid as many writes as possible to the actual memory cells. So data that is modified nevertheless stays in original form until it is rewritten much later.
The algorithms also will actively manage wear to the underlying cells and stop using areas that have high wear, meaning in theory data you thought was erased or overwritten can remain.
So overall, I would say all bets are off about erasing an SSD with certainty, other than by mechanical means.
The question hasn't even been coming up much for about ten years if not twenty in high capacity storage unit data center operations.
Long and short of it is that NEW storage is faster, better, smaller, cheaper, less power-hungry, some combination of all of the above so:
A) The goal is VERY rarely to "recycle" the old media, for use of a new user by destroying any hope of access to the data of a former user. Just give them (or yourself) "Virgin", new media, and go back to USEFUL work.
B) ALL of the storage densities had gotten so DAMNED HIGH, it takes HOURS and HOURS to do a seven-pass random over-write of a typical sized drive, solid state OR rotating. Why would a sane entity tie up a machine and power and costly human over-sight for such
unproductive nonsense?
C) "mechanical means", thermal or chemical, mostly, don't give the least damn about storage capacity. Only mass and type of material. Even so, given an appropriate means is applied to any given mass, it takes about the same time and expense to smelt or dissolve either type into unrecoverable slag or slurry, regardless of data stored or possible capacity FOR it.
So "mechanical means" it what we doos. It is cheap. It takes less time. Human time is expensive and hard to replace, once wasted.
End of data. End of problem. End of story.
And ZERO "host computer" OS or software involved.
Last batch I did, 60-plus still-good "preventive maintenance" and/or upgrade data server HDD "pulls"?
- Step One: a drillpress was depth-stop-set to ruin PCB, plus platter(s), AND NOT exit the far side,
- Step Two: Muriatic Acid was injected through the hole, then a bit of jackleg sealant.
- Step Three: They were left to "cook" for a period of time at a mildly elevated temperature.
Only THEN sent off to the ordinary scrappers of such goods, special high-security disposal credentials no longer of any concern whatsoever.
SSD? MAPP gas torch, decent exhaust extractor, soon done. Or the kitchen range with range hood for the under-resourced.
Mechanical means are all about "BFBI" - Brute Force and Bloody Ignorance.. because "ignorance" .... of any prior data ... is the actual operative goal.
KISS method applies.
Keep
It
Simple,
Stupid.