There has always been a give-and-take that comes with flash memory: Solid-state drives offer faster storage, but they come at a price, and devices wear out fairly quickly. As NAND flash technology evolves, organizations that are trying to select SSDs must also consider how many layers a drive has and how many bits it can fit per cell.
The number of layers and bits per cell that NAND drives support has increased as NAND technology has evolved. Drives can now support many layers of NAND cells on top of one another, which is known as 3D NAND. And with quad-level cell (QLC) NAND, devices can store 4 bits of data per cell.
The implications of these added factors are not limited to increasing the number of choices buyers have to weigh. They must also consider whether the added capacity of triple-level cell, or TLC, and QLC NAND is worth the potentially shorter lifespan. Measures such as wear leveling can increase the lifespan of any NAND device, but the fact remains that cells that go through more program/erase (P/E) cycles wear out faster. The more bits that fit per cell, the more P/E cycles the cells undergo and the faster they die.
For IT buyers, these are important considerations. Figuring out how to get the best capacity, speed and lifespan from the NAND flash technology that ends up in the IT department is no small task. This three-part guide will help newbies and seasoned decision-makers alike learn more about which NAND flash technology is right for them. And it can help administrators brush up on the differences between NAND types and where NOR flash fits in.
