Various methods are used to store data in computers. The most common are RAM and ROM. Unlike traditional HDDs, SSDs have no moving parts and are more compact. However, they are more expensive. They are also slower. They need to refresh data when it is updated. They are also more complex to maintain and repair.
1. Hard Disk Drive
The hard disk drive, or HDD, is the primary storage device in a computer and holds all the files saved to it. It’s like a filing cabinet for your digital files. It’s non-volatile, meaning it doesn’t require a constant power supply to retain its stored data. It uses an aluminum housing to protect its components and dissipate heat.
Each platter in a hard drive is coated with a ferromagnetic material that can be magnetized to store bits of data. Each bit represents either a 1 or a 0. When the read/write heads are passed over a platter, they change its magnetization to input data.
Each platter is divided into tracks, which are further divided into sectors. The more sectors on a track, the more storage capacity it has. However, this also increases the seek time – how long it takes for the R-W head to reach that sector from its current location. The difference between input and output devices is that an input device sends data to a computer system so it can be processed, and an output device shows or copies the results of that processing. It is only possible to send data to a computer through an input device, and it is only possible for an output device to receive data from another device.
2. Solid State Drive
Solid-state drives (SSDs) are an alternative to hard disk drives for data storage in computers. They are much faster, have lower energy consumption, and do not produce any noise.
SSDs are built with integrated circuit assemblies of flash memory. They can use traditional HDD interfaces and form factors or newer ones that improve performance, scalability, manageability, serviceability, and power loss protection. The drive’s controller reads and writes data to an underlying array of interconnected flash memory chips made from silicon. Each chip stores a single bit of data, either a 1 for a charged cell or a 0 for an uncharged cell.
When the drive is updated, each block of data is copied to a newer block. The old block is then erased and rewritten with the updated information. This process reduces write amplification, which can cause the lifespan of the drive to decrease.
3. Flash Memory
Flash memory is nonvolatile and has faster read/write speeds than hard disks. In addition, it requires less power than a hard disk drive and has no moving parts, which makes it more durable.
Flash is used in storage cards with SD and MMC formats and in USB thumb drives, and it is also included in cell phones, digital cameras, MP3 players, and video recorders. It is gaining popularity as a replacement for hard disc drives in desktop computers and laptops, and it is also being incorporated into SAN arrays.
NOR flash is used for code storage in small capacities, and NAND flash is optimized for high-density data storage. The logic in the transistors of NAND flash is arranged so that the source and drain are connected to a bit line, which reduces the number of ground wires and increases the amount of information stored per chip. A special controller chip handles logical block mapping and performs wear leveling, space reclamation, and bad block management.
4. SD Card
SD cards are used to store digital data in mobile phones, digital cameras and portable gaming consoles. They use flash memory that is faster than magnetic memory, not susceptible to normal-level magnetic fields and can be miniaturized.
They also have no moving parts and are less prone to physical failure than other data storage methods. They’re also cheap, making them a great way to add extra storage space to your devices without spending a lot of money.
SD cards come in three sizes: Standard SD, MiniSD and MicroSD. Standard SD cards are 24 x 32 mm and are 2.1 mm thick. They have nine pins (electrical contacts) and a write-protect switch. The newest versions, called UHS-II and UHS-III, have an additional row of contacts for higher performance. The highest capacity cards, called Micro SDXC, can hold up to 2 TB and have transfer speeds of up to 90 MB/s.
5. Memory Card
A memory card is a type of flash storage that saves digital information and can be transported between devices allowing you to edit and share files. They can be inserted into a slot and used much like a USB drive or flash drive. However, they are much smaller and can be stored in many more portable consumer devices. They also have a higher operating shock rating than traditional mechanical drives, being able to sustain up to 2 Gigabytes of storage.
SD cards are available in a number of different sizes with the full size, miniSD and microSD form factors being the most common. They can be found in everything from mobile phones and tablets to cameras and camcorders. The different types of SD cards differ in performance which is indicated by the speed class symbol which can be matched to a specific host device. This is important as some applications, such as high-definition video recording, can cause issues if a slower class card is used.
6. Floppy Disk
The floppy disk is a removable magnetic storage medium for computers. It consists of a flexible disk coated on one or both sides with magnetic iron oxide that computer data can be recorded and read. It is enclosed in a rectangular plastic envelope that has a sliding metal shutter that slides back when the disk is inserted into the drive to expose the disk surface to the disk drive’s magnetic head. Disks were available in three standard diameters: 8 inches (203.2 mm), 5 1/2 inches (133 mm) and 3 1/2 inches (89 mm).
A floppy disk drive has a motor that spins the disk at high speed, which reduces access time to stored data to less than 20 milliseconds. The floppy disk drive also has read/write heads that can access both sides of the disk. Data on a floppy disk is organized in sectors (angular blocks) and tracks (concentric rings at a constant radius). The earliest 3 1/2-inch floppies used 18 sectors per track, 80 tracks and two sides of the disk to store 1.68 MB of data. Higher-capacity drives were developed in the 1990s, but they never gained wide adoption.