QLC Has The Shortest Memory, MLC The Longest
If you have important data stored on an SSD sitting in a closet somewhere you might want to seriously consider plugging them in at least once a year. As you should expect, without power the NAND can lose it’s charge and forget if it was supposed to be storing a 1 or a 0. Tests have shown that consumer grade SSDs with TLC should last about a year before data loss becomes a concern, and the same for older QLC drives. The newer types of QLC are more robust and should give you 2-3 years leeway before your data starts to be at risk.
Enterprise SSDs are somewhat better, MLC should hold data perfectly for up to five years while SLC NAND could well sit for a decade before the NAND starts to lose it’s charge. Long story short; you shouldn’t consider an SSD a good alternative to a HDD or tape for long term cold storage. When you consider the NAND also has a limited lifespan when powered up, SSDs really aren’t your best choice for long term storage.
Slashdot links to the article on xda-developers which breaks down the details and offers tips on best practices for backing up data.
