computer storage devices
· Definition of computer storage devices
A storage device is a piece of computer hardware that stores, transports, and retrieves data. It has the ability to store and retain information for a short or extended period of time. It can be an internal or external device to a computer or server.
Storage medium or storage media are other words for storage device. A storage device is one of the most fundamental components of any computer.
Except for hardware firmware, it virtually completely stores all data and applications on a computer.
It is available in a variety of shapes and sizes, based on the needs and functions.
The usage of storage device
· STORING -the hard drive is the most common data storage device, but we may also utilize other types of storage devices.
· Transporting — it used to be difficult to transfer from one hard disk to another. so, we are looking for a way to link the drives. Wired or wireless media, such as pen drive can be used for this computer.
· Extracting data files — the term extract refers to the process decompressing and relocating one or more files from a compressed file to a different location.
· It provides many uses to the users as it provides great flexibility to the users .
· It helps in keeping all the important records at a synchronized place with loads of data security.
· It helps keeping a check on all the records and also helps in maintaining a check on the number of users who have access to the the data.
· It also helps in providing security to the confidential data that is very important for the user.
· With the use of data storage and other storage , it becomes easy to cross -check and audit the records easily.
Types of storage
There are four types of storage. they are ,
1. Primary storage
2. Secondary storage
3. Tertiary storage
4. Offline storage
1.Primary storage
Primary storage, also known as main memory, internal memory, prime memory. Its the main area in a computer in which data is stored for quick access by the computer’s processor. Information must be transferred to primary storage and this volatile and temporary. but at the same time its temporary as everything vanishes after the system reboot. Primary storage is comparatively limited in size especially when compared with secondary storage.in modern personal computer, primary storage is often around 4GB in size. There are 4 types of primary storage.
a) RAM
b) ROM
c) Cache memory
a) RAM
· A computer’s primary storage is known as Random Access Memory, or RAM. When we work on a file on our computer, it stores data in RAM temporarily. Opening applications, loading webpages, editing a document, and playing games are all possible with RAM. You can also jump from one activity to the next without losing your place.
· RAM is a volatile memory, which means that when the computer is shut off, it loses its data. If you copy a block of text, restart your computer, and then try to paste it into a document, your computer will ignore it. This is because it was only kept in your RAM for a short time.
·RAM stands for random access memory.
There are two types of RAMS:
– DRAM (Dynamic Random-Access Memory)
– SRAM (Static Random-Access
b) ROM
Read Only Memory is referred to as ROM. We can only read from this memory; we cannot write on it. This is a non-volatile form of memory. During the manufacturing process, the data is permanently saved in such memories. The instructions needed to start a computer are stored in a ROM. The operation is known as bootstrapping. ROM chips are utilized in a variety of electrical devices, including computers, washing machines, and microwave ovens.
ROMs come in a variety of formats:
· Masked ROM-This is the first sort of ROM with hard-wired devices, and it’s cheap. For the gadgets to work, the instructions were pre-programmed into them.
· Programmable ROM (PROM)-When people upload it for the first time, they are only allowed to make one change. The programs, however, are not erasable because the device’s fuses burn out during programming.
· Erasable programmable ROM (EPROM)-The data on this type of gadget can be erased by exposing it to UV radiation for at least 40 minutes. This is because the electoral charge is trapped inside the insulated zone during programming, but the charge is dissipated by the passage of rays.
· Electrically erasable programmable ROM (EEPROM)-Electrically, the data may be programmed and erased at least ten thousand times in just 4 to 10 milliseconds (millisecond). This is applied to specific areas and erases one byte at a time, making the operation slow.
· Flash ROM- It serves as a storage medium in the computer. It’s also electrically erasable and reprogrammable. However, in this case, 512 bytes of data are deleted at a specific moment.
C) Cache memory
· The central processor unit of a computer uses cache memory to minimize the average time it takes to access memory. The cache is a smaller, quicker memory that holds temporary data. copies of data from the most often used mainframe. Locations in memory As long as the majority of memory accesses are safe. The average latency to cached memory locations is Memory accesses will be faster than cache accesses.to the main memory’s latency.
Cache is a small, quick memory that is usually found on the CPU.
Cache memory can be accessed/processed more quickly than RAM;
It is used to store data/operations that are common, expected, and regularly used.
It is closer to the CPU than RAM; it is located between RAM and the CPU; it is on the same board as the CPU; and it has a faster read/write speed.
2.Secondary storage
Secondary storage devices are referred to as auxiliary memory or external memory. Because secondary storage devices are volatile, data is not lost when the power is turned off, and all data is saved for a long period. Secondary storage devices are slower than primary storage devices in terms of data access, but they are also less expensive. Because primary storage devices are necessary for data processing, these secondary storage devices are useless without primary storage devices. The data is first transferred into primary memory, and then it is converted into executable code.
Examples for secondary storage — hard disk ,solid slate devices , CD, DVD, floppy disks.
a. Hard disk drive (HDD)
A hard disk drive is made up of platters, which are rotating metal disks. There are millions of microscopic particles on each spinning disk that can be magnetized to represent bits (1s and 0s in binary code). To put digital information onto the HDD, an actuator arm with a read/write head scans the spinning platters and magnetizes fragments, or detects magnetic charges to read information from it.
(HDD) hard disk drives are used for TV recorders, servers and laptop and pc storage.
3.Tertiary storage
This type of storage is generally not considered to be important and is generally not a part of a personal computers.it involves mounting and unmounting of mass storage data which is removable from a computer device. this type of storage holds robotic functions. and it does not always require human intervention and can function automatically. The main objective of the tertiary storage level is to provide huge storage capacity at law cost. several types of storage devices are available to be used at the tertiary storage level in hierarchical storage system (HSS).they include magnetic types , optical types optical tapes these storage devices are composed of fixed storage drives and fixed to computer system.
Its primarily used for archiving rarely accessed information since it is much slower Than secondary storage. this is primarily used For extraordinarily large data stores ,accessed without human operators.
4. Offline storage
Any storage medium that must be physically inserted into the system each time a user wishes to access or change data is referred to as offline storage. Any sort of internal or external storage that can be quickly removed from the computer qualifies as offline storage.
Removeable storage is another name for offline storage. Offline storage is typically portable and can be utilized on a variety of computers.
In the event of unforeseeable situations, offline storage is employed for transit and backup protection. For example, hardware failure as a result of a power outage or files infected by a computer virus.
Floppy disks, magnetic tape compact disks, and USB thumb drives are all examples of offline storage.
Types of computer storage devices
1. Magnetic storage devices.
Magnetic storage systems are the most widely utilized storage technologies nowadays. These are inexpensive and simple to obtain. These can store a lot of data thanks to the magnetized media.
When the gadget is connected to the computer and the magnetic polarities are used, a magnetic field is formed. The device is capable of reading and storing binary data.
· Floppy disk — Also known as a floppy diskette, it is a removable storage device which is in the shape of a square and comprises magnetic elements. When placed in the disk reader of the computer device, it spins around and can store information. Lately, these floppy disks have been replaced with CDs, DVDs and USB drives.
• Hard Drive — The disk controller on the motherboard is directly connected to this major storage device. It is necessary to install every new program or application to the device, so that is an essential storage space. Software applications, photos, videos, and some other media can all be saved on a hard drive, and terabyte-sized hard drives are now widely available.
• Zip Disk — Introduced by Iomega, the Zip Disk is a removable storage device with a storage capacity of 100 MB, which was later raised to 250, and finally 750 MB.
- Magnetic Strip — A magnetic strip with digital data is attached to the device. A debit card with a stripe is the most appropriate example for this.
1. Optical storage
Optical discs are optical storage media for computers. They store data via deformations on the surface of a circular disc. A laser diode illuminates the surface of an optical disc drive, and computers use the reflection to access the data. The storage of optical data is non-volatile. Permanent diformities are possible (read-only media).
• CD ROM (Compact Disc Read-Only Memory) — A CD ROM is an external device that may store and read data in the form of audio or software.
- BLUE-RAY DISK- It was released in 2006 as a single-layer disc with a storage capacity of 25 GB. A 50-gigabyte dual-layer disc is now available. It contains a specific blue laser that must read numerous layers of bumps. With variations, the storage capacity can reach 128 GB.
- DVD (Digital Versatile Disc) is an optical storage media that can be read, recorded, and rewritable. Users can use this device to record and then connect it to the system. This is widely used by CCTV and has a capacity of 9.4 GB. It enables reading.
1. Flash memory
These storage devices have supplanted both magnetic and optical storage methods. They’re easy to use, portable, and easily available. They’ve progressed into a more cost-effective and handy data storage solution. a flash drive
For data storage and transport, it’s widely used in consumer gadgets, enterprise systems, and industrial applications. Flash memory devices are available in a wide range of designs and sizes. Like as
USB flash drive, jump drive or t
- USB Drive — Also known as a pen drive, this storage device is compact and portable, with storage capacities ranging from 2 GB to 1 TB. It has an integrated circuit that allows it to both store and replace data.
- Memory Card — A memory card can be used to store photographs, movies, and audios and is compatible and compact in size. It is usually attached to smaller electrical and computerized equipment such as mobile phones or digital cameras.
• Memory Stick — Originally developed by Sony, a memory stick can store more data and allows for easy and speedy data transfer. Various different versions of memory stock were released later.
- Secure Digit Card (SD Card)- It’s also known as a Secure Digital Card, and it’s used to store data in a variety of electronic devices. It comes in mini and micro sizes. An SD card is usually inserted into a separate slot on a computer. Separate USBs are available in which these cards can be inserted and subsequently connected to the computer if they do not have one.
- Online cloud storage devices
The term “cloud storage” refers to a sort of network storage. Through his work on ARPANET, which connected people and data from all over the world at any time, Joseph Carl Ronette Lickliter is credited with developing cloud computing in the 1960s.
The phrase “cloud computing” refers to data centers accessible via the Internet where users can preserve their databases and files. This information is easily accessible via the internet at any time and from any location.
A hosted object service, file storage, and block storage are the three forms of cloud storage. Each of these cloud storage options has its own set of benefits.
· PCloud
· MEGA
· One Drive
· Sync.com
· IDrive
The advantages of cloud storage are :
· Files can be backup online.
· Files can be shared with others.
· Files can be accessed from anywhere with internet connection.
· Big files can be shared using links.
What are the most used storage devices
· The most common used storage devices in today’s Optical discs and flash memory devices are most popular, and to much lesser extent removable hard disk drives. In enterprise uses, magnetic tape is predominant. Older examples are floppy disks, Zip disks, or punched cards.
Optical storage devices — such devices used lasers and light to detect and store .they are cheaper in comparison to USB drives and can store more data.
· The most common optical storage devices are drives that read and write CDs, DVDs and blue- ray disks .
· Flash memory devices -these storage devices have now replaced both magnetic and optional storage devices. They are easy to use ,portable and easily available and accessible.
· NAND and NOR are the two primary types of flash memory. NAND flash memory is commonly used for storing and transferring general-purpose data, whereas NOR flash memory is typically used for storing digital configuration data. The most popular form is NAND, which may be found in USB drives and SD cards.
· Online cloud storage -the term cloud computing is used to describe the data centers available for users over the internet where they can save their database .
Characteristics of computer storage devices
· Storage technologies at all levels of the storage hierarchy can be differentiated by evaluating certain core characteristics. these core characteristics are volatility , mutability ,accessibility , and addressability.
1. Volatility
Non-volatile memory
Even if it is not constantly supplied with electricity, the stored information will remain. It is appropriate for long-term data storage. Nowadays, it is used for the majority of secondary, tertiary, and off-line storage.
Volatile memory
Requires constant power to maintain the stored information. The fastest memory technologies of today are volatile ones. since primary storage is required to be very fast, it predominantly uses volatile memory.
2. Differentiation
DRAM stands for dynamic random access memory.
A type of volatile memory that also requires the stored information to be re-read and re-written or refreshed on a regular basis, or it will vanish.
Memory that is static
A type of volatile memory similar to dram in that it does not need to be refreshed as long as power is applied (it loses its content if power is removed )
3. Mutability
Mutable storage or read/write storage
Allows for the overwriting of data at any time. A computer would be useless for many tasks if it did not have some amount of read/write storage for primary storage. Read/write storage is commonly used for secondary storage in modern computers.
Storage that is only read-only
Retains the information stored at the time of manufacture, whereas write once storage (Write Once Read Many) allows the information to be written only once after the fact. These are referred to as immutable storage. Tertiary and off-line storage make use of immutable storage. CD-ROM and CD-R are two examples.
Storage that is slow to write but fast to read
Read/write storage, which allows data to be read and written
4. Accessibility
Random access
Any storage location can be accessed at any time in roughly the same amount of time. Such a feature is ideal for both primary and secondary storage.
Sequential access
Because information will be accessed in a sequential order, one after the other, the time it takes to access a specific piece of information depends on which piece of information was last accessed. Such a feature is typical of off-line storage.
5. Addressability
Location-addressable
The numerical memory address of each individually accessible unit of information in storage is used to select it. Modern computers typically limit location-addressable storage to primary storage, which is accessed internally by computer programs, because location-addressability is very efficient but burdensome for humans.
File addressable
Information is divided into variable-length files, and a specific file is selected using human-readable directory and file names. The underlying device is still addressable, but a computer’s operating system provides file system abstraction to make the operation more understandable. File systems are used in secondary, tertiary, and off-line storage in modern computers.
Content-addressable
Each individually accessible unit of information is chosen based on the contents (part of) which are stored there. Software (computer program) or hardware (computer device) can be used to implement content-addressable storage, with hardware being the faster but more expensive option. Hardware content addressable memory is frequently used in the CPU cache of a computer.
References
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