I just concluded a decade long experiment.

[happydisciple@mendeddrum.org]

@Aaron_DeVries @swope A lot of physical processes are thermally activated. At higher temperatures the barrier between two (meta)stable states is often easier to cross, which is why things can go wrong at higher temperature.

If it is, as I read it, bits _written_ at higher temperature having a shorter lifetime even at lower temperature after, I can imagine that the state written at higher temp isn’t as far down into the local energy minimum.

#physics #phycisist

[simonzerafa@infosec.exchange]

@Aaron_DeVries

Was the flash memory in that USB Drive older SLC type?

In which case I would anticipate that it would have a longer data retention. 11 years is impressive though.

What make and model was that drive?

[astraleureka@social.treehouse.systems]

@valpackett @swope @Aaron_DeVries I have heard some colloquial stories of "cold"/unpowered backups on flash becoming completely unusable after being stored in a hot safe. it would be interesting to see exactly how sensitive and reliable this effect is

[swope@mstdn.plus]

@happydisciple

Yes, I imagine that something like that is going on. And the manufacturer is honest about the 35C max operating temperature.

For the user, they write a bunch of data and immediately verify the data are good -- not looking closely at the temperature log. But hours/days later their files become corrupted.

It's something to be aware of, and a curious physics question.

@Aaron_DeVries

[swope@mstdn.plus]

@job
No, I think it's more like using hot glue on plastic. While it's hot the glue sticks to the plastic, but as it cools your whole crafting project falls apart.

(Just a metaphor, not the physics)

@evey @Aaron_DeVries

[evey@chaos.social]

@job @swope @Aaron_DeVries more like the energy difference of the electrons, the hotter they are the easier they migrate. The colder they are the slower they go. Or something like that

[swope@mstdn.plus]

@evey

I think that's intuitive for storage, but the hot-at-write-time weakness may be a little different.

I'm imagining an array of cups and the drive controller is pouring water in them as the write operation. When the system is hot, the cups are jiggling and aiming the carafe is shaky. Not a lot of water gets in the intended cups, and some spills into the wrong cups. Enough goes in for the theshold of the immediate validity check, though.

@job @Aaron_DeVries

[swope@mstdn.plus]

Then even at normal temperature, slow evaporation over days means the amount of water in those cups drops below threshold in enough cups to break ECC margins -- corrupting the files.

I don't have a deep enough understanding of the physics to tell you if that analogy has much validity. But this is my hunch.

@job @Aaron_DeVries @evey

[aaron_devries@mastodon.social]

@simonzerafa

I'm unsure if it's SLC or something else, I suspect not as it's an old/cheap 16 gig Lexar USB drive.

[gustodon@mas.to]

@Aaron_DeVries Informative AF. ️

[peterrenshaw@ioc.exchange]

@Aaron_DeVries did you use silica bags to reduce the chance of moisture buildup?

[samloonie@mstdn.ca]

@Aaron_DeVries Another helpful factor in your experiment is that burial would have protected the flash drive from cosmic rays.

[heafnerj@scholar.social]

@Aaron_DeVries Oh I don’t think it’s useless at all!