Wear Leveling
What is wear leveling?
Wear leveling is a technique by which the SSD controller attempts to prolong the lifespan of the SSD by ensuring that data writes are distributed evenly among available cells.
Because each cell can only endure a finite number of writes/erasures, it is possible that, without wear leveling, some cells would be unevenly stressed, which would prematurely end the life of the entire SSD.