Why Your SSD Will Outlive Your Hard Drive: The Engineering Behind Flash Memory
When you save a file to a solid-state drive, something happens at the atomic level that your hard drive could never accomplish. Electrons tunnel through an insulating barrier and become trapped in a microscopic cage, where they can remain for years without power. This is the fundamental magic of flash memory—and understanding it explains everything from why SSDs slow down when full to why they eventually wear out. The first commercial flash memory chip appeared in 1988, but the technology traces back to a 1967 paper by Dawon Kahng and Simon Sze at Bell Labs. They proposed storing charge in a transistor’s floating gate—a conductive layer completely surrounded by insulator. Nearly six decades later, every NAND flash cell operates on this same principle, even as manufacturers have stacked cells hundreds of layers high and squeezed multiple bits into each one. ...