3.3: Peripherals

Hard Disk Drives

A hard drive or hard disk drive (HDD) is a type of data storage device that is used in laptops and desktop computers. An HDD is a “non-volatile” storage drive, which means it can retain the stored data even when no power is supplied to the device. Operating systems (OS) tell the HDD to read and write data as needed by programs. The speed that the drive reads and writes this data is solely dependent on the drive itself.

HDDs started as massive, room-filling devices with a capacity of about 3.75 megabytes (MB). Today, by comparison, an HDD that fits easily in a desktop computer can have upwards of 18 terabytes worth of storage.

HDDs are the most affordable storage type because they have the most efficient cost per gigabyte. As storage capacity increases, the price of smaller HDDs decreases.

Solid State Drives

A solid state drive (SSD) is a storage device that saves your files, photos, and applications using memory chips instead of physical moving parts like an HDD. These chips are known as flash memory, and they can store data by harnessing electrical charges — even when powered off.

Unlike traditional hard drives with spinning parts, SSDs are — as their name implies — made of solid components. Without needing to wait for disks to start spinning or read/write heads to swing into place, solid state drives offer dramatically faster speeds, more durability, and better energy efficiency.

Diskettes

Early computers used floppy disks, which could be inserted into a disk drive in the computer. Data was stored on a magnetic disk inside an enclosure. These disks ranged from 8″ in the earliest days down to 3 1/2″.

• 8" ⇒ 80 KB
• 5 ¼" ⇒ 360 KB (1.2 MB in HD)
• 3 ½" ⇒ 720 KB (1.44 MB HD)

External Drives

An external hard drive is a portable storage device that connects to your computer or other devices through interfaces like USB, Thunderbolt, or Wi-Fi. Unlike an internal drive, which is permanently installed within a computer and serves as the main storage for operating systems and essential software, external hard drives provide additional, portable storage options. They come in two main types:

1. Desktop external hard drives: These typically offer larger storage capacities and faster data transfer speeds, making them ideal for serious users who need extensive space for tasks like digital editing and large game installations.
2. Portable external hard drives: These are smaller, more compact devices designed for users who need to carry their data with them.

Modern external hard drives can range from traditional spinning disk drives (HDDs) to ultra-fast solid-state drives (SSDs), offering capacities from a few hundred gigabytes to multiple terabytes. For optimal performance, consider a high-capacity external SSD that combines speed and storage. 

Optical Discs

Early versions of optical discs were created by researchers in the 1960s, and optical dick technologies appeared on the market in the early 1980s in the form of CDs and DVDs. At first these were used mainly for music and movies. CD-ROMs were read-only, and not a writable medium.

Standard CDs could hold about 700 megabytes of data, enough for 80 minutes of music or about 500 photos. But the ever-growing amount of computer-generated data created the need for a new form of high-capacity removable storage.

In recent years, optical discs have gradually lost popularity since large volumes of data can inexpensively be stored in the cloud. But the durability and high storage capacity of optical discs ensure they will continue to be used for years to come to create archives of important information for business and government.

Today’s optical discs can store terabytes of data and offer up to 100 years of reliable data retrieval — a formidable combination of capacity and durability.

USB Flash Drive

Around the turn of the century, a new portable storage technology was being developed: the USB flash drive. This device attaches to the universal serial bus (USB) connector, which became standard on all personal computers beginning in the late 1990s. As with all other storage media, flash drive storage capacity has skyrocketed over the years, from initial capacities of eight megabytes to current capacities of 64 gigabytes, and still growing.

In early personal computers, specific ports were designed for each type of output device. The configuration of these ports has evolved over the years, becoming more and more standardized over time. Today, almost all devices plug into a computer through the use of a USB port. This port type, first introduced in 1996, has increased in its capabilities, both in its data transfer rate and power supplied.

SD cards

Secure Digital card (SD) is a memory card format developed by the SD Card Association (SDA) for use in portable devices.

It was introduced in 1999 as a joint effort between SanDisk, Panasonic (Matsushita Electric) and Toshiba, as an improvement over MultiMediaCards (MMC), and has since become the industry standard.