Comparing pSLC and SLC
If you have researched NAND flash storage recently, you may have encountered terms like pSLC and SLC. Understanding what these terms mean and how they differ from each other has an enormous impact on your ability to get the best storage for your application. There are big differences between these kinds of storage, and in fact, the differences between all NAND flash storage formats are significant enough to have a major impact on the functioning of your device. Choosing the wrong one could lead to serious device failure. For consumer users, device failures are frustrating and inconvenient. However, the stakes are even higher for industrial users whose applications are used in critical areas, like transportation or healthcare. This information will help you make an informed decision when you’re looking at pSLC and SLC flash options.
SLC stands for single-level cell. It is the form of NAND flash storage that is recommended for use in the vast majority of industrial grade applications. SLC flash storage works by writing one bit of data per cell in the memory device. The cells in SLC flash are the largest of any NAND flash product, which is one of the factors that contributes to its reliability.
The reliability difference between SLC flash and other kinds of flash storage can be significant. In fact, SLC flash can be as much as 300 times more reliable than lower grades of NAND flash. This doesn’t mean that SLC flash should be used in every product. MLC flash, a commercial grade alternative, is better suited for consumer products for a number of reasons. However, industrial users can generally not afford to experience that kind of reliability reduction.
pSLC stands for pseudo single-level cell. pSLC flash uses MLC NAND flash components, but the entirety of each cell is not used for storage, thus limiting the amount of data that can stored on each cell. These products are often promoted as industrial grade, but pSLC and SLC are very different.
The cells in pSLC flash are smaller, since they are MLC cells. This means that they are far more prone to corruption, cell crosstalk, read disturb errors, and data retention problems. Unexpected power loss is also an issue. Although pSLC limits data storage per cell, it doesn’t have the device architecture benefits of standard SLC, so it loses most of its advantages.
Delkin’s product team is available to help OEMs make complicated decisions and find a memory solution that meets their needs. Contact us with your questions or to get additional information about pSLC and SLC flash.