How Long Do Hard Drives, SSDs and Memory Cards Actually Keep Data?

Fleet failure rates are not archive lifetimes

Hard drives in service report a 2025 AFR of 1.36%, down from 1.57% in 2024. Across 115,638,676 drive-days observed in 2025, 4,317 drives failed. But this fleet data encapsulates mechanical issues experienced by a powered-on drive in a working environment.

Drive failure studies track a fleet's uptime, not its unpowered data retention. They don't describe how long an unpowered drive can keep data. A drop in fleet AFR, as seen from 2024 to 2025, may indicate improved technology, but it's about working drives. The practical effects of unpowered storage remain a separate question.

What SSD retention specs actually say

An enterprise SSD has a JEDEC powered-off retention requirement of 3 months at 40°C. The 3-month retention figure assumes the drive has reached the end of its rated life after a minimum of one full write- and erase cycle. If an enterprise SSD exceeds its maximum unpowered period, data may become unrecoverable when power is reapplied.

SSD data retention typically holds for a set unpowered time after a full drive cycle, not permanently. A consumer SSD would not automatically enjoy the same 3-month 40°C shelf life. Specific specs detailing consumer SSD retention while unpowered remain.

Memory cards have their own retention clocks

A flash memory card's unpowered retention depends on its internal wear and storage temperature. A high-end ATP microSD card is rated for 5 years of data retention at 55°C if wear is minimal. But.

While SD and microSD retention figures depend in part on temperature,. MicroSD storage manufacturers often separate the concerns of reliably retaining a bit in a temperature-controlled environment (such as in controlled environments), from reliably soaking up ambient moisture in environments that can, quite literally, rain.

Why shelf storage is condition-sensitive

A commodity microSD card might project 10 years of data retention at 25°C. But managed internal temperature is key for these projections. MicroSD platforms are tested under various conditions. They also test the possible causes of memory card failure over time: "It's not just the temperature. It's the sticky Singaporean temperature. Environmental factors like humidity and physical stress can affect data retention." Data retention is not theoretical; it's practical.

What the missing comparison should be

Consumers often refer to hard drives as a "shelf storage" medium. Hard drives are often assumed to keep data indefinitely when powered-off, but environmental factors like dirt, damp, or physical shock can affect retention. However, a hard drive's deserving shelf reputation is but a standard reporting trope. While general truths about hard drives are widely applicable, specific facts about unpowered retention are harder to isolate.

Practical conclusion

Storage manufacturers across flash, optical and magnetic formats frame retention as a junction point between wear, temperature and storage environment. Devices in storage should be checked regularly, accounting for their wear. Memory cards are more sensitive than flash drives. Optical discs have certified archival life if handled correctly, while magnetic tape retains data for its specified lifespan.

Supporting guarantees on unpowered data retention remain fragmented by format and publication. Suitable documentation cannot be gathered to advise a patron searching for an archive art project. The industry's myriad manufacturers, each with their own recommended environments, standards, and claims, leave a patron stranded. For archival needs, we recommend consulting the standards body of the archive medium in question for the best archive grade.