SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/tech-ssd-wear-leveling

Flash memory cells wear out after many writes. How does an SSD stretch its life?

It spreads writes evenly across cells (wear leveling).

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  1. It spreads writes evenly across all cells ✔
  2. It writes everything twice
  3. It reserves one fixed cell for every address

Why: Flash cells tolerate only a limited number of program and erase cycles. The SSD's translation layer remaps logical addresses so writes are distributed across cells instead of wearing out one location early.

Huh, didn't know that: Flash in SSDs is organized in pages, and a group of pages is called a block.

The dad joke
Why are SSDs so fair? They never let one cell do all the work.
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References

Answer: It spreads writes evenly across all cells. Flash cells tolerate only a limited number of program and erase cycles. The SSD's translation layer remaps logical addresses so writes are distributed across cells instead of wearing out one location early.

  1. OpenStax Introduction to Computer Science 5.5: Memory Hierarchy openstax.org/books/introduction-computer-science/pages/5-5-memory-hierarchy
    the translation layer tries to change the mapping to ensure that accesses are equally distributed among different cells
    Checked 2026-10-10.

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