Understanding drive endurance
There is usually an endurance rating associated with both mechanical drives and SSDs. The endurance of a drive defines multiple things, such as its maximum performance, workload limits, and its mean time between failures (MBTF). Owing to their contrasting natures, the endurance of mechanical drives and SSDs is measured in differing ways.
The endurance ratings for both types of drives are expressed in different ways. As explained earlier, cells in the NAND flash can go through a finite number of P/E cycles. Once this limit is reached, the cell will become defective. The endurance rating for SSDs is a function of the number of P/E cycles for which the NAND is rated. It is important to note that NAND cells only wear out for write (program) and erase operations. For read operations, this overhead is negligible. The metrics to measure the endurance of SSDs are as follows:
- Drive Writes per Day (DWPD): The DWPD rating shows how many times you can overwrite...
