The unpowered SSDs in your drawer are slowly losing your data

Re:The unpowered SSDs in your drawer are slowly losing your ... by rossjudson on Tuesday November 25, 2025 @12:13AM (#46042554)

Keep in mind that when flash memory is read, you don't get back 0 or 1. You get back (roughly) a floating point value -- so you might get back 0.1, or 0.8. There's extensive code in SSD controllers to reassemble/error correct/compensate for that, and LDPC-ish encoding schemes.

Modern controllers have a good idea how healthy the flash is. They will move data around to compensate for weakness. They're doing far more to detect and correct errors than a file system ever will, at least at the single-device level.

It's hard to get away from the basic question, though -- when is the data going to go "poof!" and disappear?

That is when your restore system will be tested.

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Re:The unpowered SSDs in your drawer are slowly losing your ... by londons_explore on Tuesday November 25, 2025 @02:38AM (#46043283)

Unless I am misunderstanding the communication protocol between the flash chip and the controller, there is no way for the controller to know that analogue value. It can only see the digital result.

Maybe as a debug feature some registers can be set up adjust the threshold up and down and the same data reread many times to get an idea of how close certain bits are to flipping, but it certainly isn't normal practice for every read.

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Re:The unpowered SSDs in your drawer are slowly losing your ... by spixy on Tuesday November 25, 2025 @02:17PM (#46049559)

return value < 0.5 ? 0 : 1;

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