Am Thu, Feb 20, 2025 at 11:40:48PM +0100 schrieb Frank Steinmetzger: > Another thing to consider: don’t put it into the safe for a year without > powering it up. As was explained in a previous mail, QLC uses sixteen > different levels of charge inside one single flash cell. The chance of a bit > flip increases the longer the SSD is powerless and charge slowly (very > slowly) dissipates. It’s hard to find exact numbers, and it’s more of a > statistical question. Could be a research topic for a slow Sunday. ;-) > Also, don’t you live in a hot area?
I knew I’ve seen this data in the past, but couldn’t remeber where and in what context. I just stumbled upon the relevant info again. If you search for "jedec temperature and data retention" you find this PDF: https://www.jedec.org/sites/default/files/Alvin_Cox%20%5BCompatibility%20Mode%5D_0.pdf It contains establised standard values for flash durability. On slide 28 it says: Client-class SSDs should retain their data w/o power for 1 year if used 8 hours/day at 40 °C and kept at or below 30 °C when off. There is also a table for other temperatures; the time is cut in half for 5 degrees more. Mind you, that PDF is 15 years old, TLS had just been released to the public one year earlier according to https://en.wikipedia.org/wiki/Multi-level_cell#Triple-level_cell -- Grüße | Greetings | Salut | Qapla’ Please do not share anything from, with or about me on any social network. Some are so convinced, they don’t even know anymore of what.
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