What is a solid-state drive?
For decades, data was stored primarily on mechanical hard drives. These traditional hard disk drives (HDDs) are mostly based on moving parts, like a read/write head that goes back and forth to gather data. This makes HDDs the likeliest computer hardware component to fail.
This article contains:
- What is a solid-state drive?
- What are solid-state drives used for?
- What are the different types of SSDs
- Get the best performance from your SSD
The new solid-state drives work completely differently. They use a simple memory chip called NAND flash memory, which has no moving parts and near-instant access times.
Early experiments with SSD-like technology started in the 1950s, and by the 1970s and 1980s they were being used in high-end supercomputers. However, the technology was extremely expensive, and the storage capacity was small (2MB-20MBs) compared to the ludicrous 5-digit prices. SSD technology was used occasionally in the military and aerospace sectors, but it wouldn’t be used in consumer devices until the 1990s .
In the early 1990s, hardware innovations caused SSD prices to drop. However, the lifespan and size were still an issue: An SSD had a lifespan of roughly 10 years. It wouldn’t be until the late 2000s that SSDs would start to become more reliable and to provide decades of continuous usage at acceptable access speeds.
The memory chips on an SSD are comparable to random access memory (RAM). Instead of a magnetic platter, files are saved on a grid of NAND flash cells. Each grid (also called blocks) can store between 256 KB and 4MB. The controller of an SSD has the exact address of the blocks, so that when your PC requests a file it is (almost) instantly available. There’s no waiting for a read/write head to find the information it needs. SSD access times are thus measured in nanoseconds.