Solid-state drives (SSDs) come in several types, differentiated by interface, form factor, and protocol. These variations affect speed, capacity, and use cases.
Unlike traditional hard drives, SSDs use flash memory to store data persistently and randomly access it without moving parts. This results in faster read/write speeds, lower power consumption, and greater durability.
The three primary types of SSDs are:
| Form Factor | Dimensions | Typical Use Cases |
|---|---|---|
| 2.5-inch | 76.2 x 100.45 x 7 mm | Laptops, desktops (replaces HDDs) |
| M.2 | 22 x 80 mm (most common) | Ultrabooks, high-end laptops, desktops |
| Add-in card | Varies (PCIe slot size) | High-performance desktops, servers |
Most confusion arises from interface and protocol differences. SATA SSDs use the older AHCI protocol, while NVMe SSDs use the newer NVMe protocol designed for flash storage. NVMe SSDs typically offer higher performance due to lower latency and parallel data paths.
Many assume all SSDs are equally fast. In reality, speed varies dramatically based on interface and protocol. For example, a SATA SSD maxes out at 600 MB/s, while an NVMe SSD can reach 7,000 MB/s.
Another myth is that SSDs wear out quickly. While flash memory cells degrade over time, modern SSDs typically last 5-10 years under normal use, according to Backblaze's drive statistics.