Over the past decade, flash storage has undergone significant advancements. While the capacity and density of flash storage have increased, its endurance and performance have declined. However, a solution called pseudo-SLC has emerged, aiming to bring back the performance and long lifetimes of the original SLC flash drives.
SLC, or single-level cell, was the first generation of flash drives and worked with one bit per cell. In contrast, today’s quad-level cell (QLC) drives store four bits per cell, providing higher storage density but sacrificing performance and reliability. Pseudo-SLC drives use multi-level cell (MLC), triple-level cell (TLC), and QLC flash dies but mimic SLC by utilizing only one voltage level per cell, eliminating the drawbacks associated with multiple voltages.
Pseudo-SLC drives find applications in specific scenarios. For example, in edge computing workloads where durability is crucial, especially in remote locations with limited physical maintenance visits like IoT applications and military, oil, and gas industries. Additionally, high-end transactional workloads in the enterprise may benefit from pseudo-SLC’s performance.
However, there are drawbacks to pseudo-SLC. It reduces the capacity of MLC, TLC, and QLC drives significantly, by 50%, 66%, and 75% respectively. Additionally, pseudo-SLC comes with a higher cost compared to regular flash storage, making it suitable for specialized use cases.
Several companies offer pseudo-SLC products targeting embedded, remote, industrial, and IoT workloads. ATP Electronics, Hyperstone, Sabrent, Silicon Power, Smart Modular Technologies, and Swissbit are among the manufacturers providing pseudo-SLC solutions with varying features and connectivity options such as PCIe, M.2, and SATA. These products cater to a range of applications, including POS devices, routers, switches, automotive, medical, and industrial applications, as well as IoT and boot for embedded systems.
