SSD (Solid State Drive) units are storage devices that store files and programs just like hard disk drives, but use flash memory chips to store data, instead of storing data on a magnetic disk. Because data is stored electronically rather than magnetically, SSDs are way faster than hard disk drives for two reasons. First, no conversion between magnetic information into electronic information is needed. And second, there are no mechanical parts, so data is readily available, while on hard disk drives you need to wait until the heads move to the area where data is stored, which takes some time. In this short tutorial we will show you how SSD units look like inside and what are their main components.

By the way. Since data is stored inside memory chips, SSD is not a disk, therefore the term “SSD disk” is wrong: prefer the term “SSD unit.”

Let’s first start talking about the external format. SSD’s can be found on several different form factor, i.e., physical sizes. The most common are 2.5” and 1.8,” because these are the same sizes used by hard disk drives targeted to laptops. It is important to know that the first market segment that SSD manufacturers targeted was the mobile market, not the desktop market, for two main reasons: SSD’s consume less power than hard disk drives (this difference may be negligible on a single desktop computer, but for a user running a laptop on batteries, every little difference counts to extend battery life) and are immune to impact (i.e., you can shake, throw and drop SSD’s and your data will still be intact; if you try the same with a hard disk drive you can damage the drive and end up losing all your data).

SSD’s can be also found with several different interfaces, but the SATA interface is the most common.

In Figure 1 we have an example of a 2.5” SSD based on the SATA interface, being the most popular format for SSD units.

SSDFigure 1: 2.5” SSD.

Now let’s see how the inside of an SSD unit looks like.


Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.