The pros and cons of flash memory

Flash memory’s NAND technology provides fast, compact, non-volatile storage for SSDs, smartphones and memory cards, using 3D stacking and TLC/QLC cells to increase density and lower cost per gigabyte. Its drawbacks include higher price than hard drives, limited program-erase cycles—especially for QLC—and slower speed than system RAM, mitigated by wear-leveling, error correction and garbage-collection controllers. Ongoing research into alternatives such as phase-change, MRAM and ferroelectric memory has yet to produce a mainstream replacement.