DWPD – Drive Writes per Day – refers to the endurance of an SSD, as in writing data in the amount of its total capacity size before it wears out in a warranted period, typically 5 years, although it could be shorter. A 1DWPD rating for a 15TB SSD mean that it can sustain having 15TB of data written to it daily for its warranted period. An alternative way of presenting an SSD’s endurance (working life) is to say that it supports a fixed number of TB written (TBW). A 15TB SSD with a 26,700TBW rating will last for 5 years at a 15TB/day writing rate.