solidstatedisk

A solid-state disk (SSD) is a non-volatile storage device that retains data without moving parts, using flash memory instead of magnetic disks. Modern SSDs rely on NAND flash and a dedicated controller to manage data placement, wear leveling, and error correction. They are commonly connected via SATA or PCI Express interfaces, with the latter often using the NVMe protocol for higher throughput.

An SSD typically comprises NAND flash memory, a flash controller, and a DRAM or non-volatile cache. The controller handles wear leveling, bad block management, garbage collection, and error correction codes. Features such as TRIM support help the operating system reclaim unused space, maintaining performance over time. Data is organized into blocks and pages within the flash memory.

Compared with traditional hard disk drives, SSDs offer much lower latency and significantly higher random read/write performance, especially with PCIe/NVMe. They have no mechanical movement, making them more power-efficient and reliable in mobile devices. However, flash memory has finite write endurance; manufacturers publish endurance ratings like TBW (total bytes written) or DWPD (daily writes per day). Real-world lifespan is usually adequate for typical workloads.

SSD form factors include 2.5-inch drives for SATA, M.2 modules, and PCIe add-in cards. The adoption accelerated with 3D NAND stacking and the NVMe protocol. First consumer SSDs appeared in the late 2000s, gaining popularity in the 2010s and becoming common in PCs and servers.

SSDs are widely used for operating systems, applications, and data workloads requiring fast access. They are more expensive per gigabyte than hard drives, though prices have fallen. Suitability depends on capacity, endurance, and performance requirements.