Fake Flash: Counterfeit Storage That Lies About Its Capacity
Fake flash is counterfeit storage whose controller reports a larger capacity than the NAND actually present; writes beyond the real capacity are silently lost, so the card looks fine until data is read back. Detect with full-capacity write-verify tools like h2testw or F3.
Fake flash is counterfeit storage — a microSD card, USB stick, or SSD whose controller is programmed to report a larger capacity than the NAND actually present (e.g. claiming 2 TB while holding 32 GB). The filesystem trusts the advertised size, so writes beyond the real capacity are silently discarded or wrap around over earlier data; everything looks fine until files are read back corrupt or missing. Detection requires write-verifying the FULL capacity: tools like h2testw (Windows) or F3 (`f3write`/`f3read`, Linux/macOS) fill the device with test patterns and read them back. A quick format or partial copy proves nothing — the first gigabytes are usually real flash. Fake flash is most common on marketplace platforms (AliExpress, eBay, commingled third-party Amazon inventory), frequently as convincing clones of name-brand cards. In one 3-year, 351-card endurance survey, 35 cards — 10% of everything acquired — turned out to be fake flash (see microSD endurance test). Practical defenses: buy from authorized retailers, verify capacity on arrival, and treat prices far below the going rate per gigabyte as the classic tell.