External memory storage refers to any type of storage device that is not inside a computer’s main storage or memory. It enables users to store data externally from a computer’s primary storage at a relatively low cost. External storage devices include external hard drives, USB flash drives, SD cards, external SSDs, CDs, DVDs, and other removable media. These allow users to expand their storage capacity, take data with them, back up important files, and more. They connect to a computer externally, typically through USB, Thunderbolt, eSATA, or other ports. Overall, external storage provides affordable, flexible storage solutions to complement a computer’s internal storage.
Types of External Memory Storage
External memory storage comes in several different forms that each offer their own advantages and use cases. Some of the most common types of external memory storage include:
Hard Drives
External hard drives use magnetic disks to store data and connect via USB, Firewire, eSATA, or wirelessly. They offer high capacities of hundreds of gigabytes to terabytes but are mechanical and less durable than solid state options.
Sources: TechTarget, Wikipedia
Solid State Drives (SSDs)
External SSDs use flash memory with no moving parts, making them faster and more durable than HDDs. Capacities are smaller than HDDs, typically less than 2TB. They connect via USB, Thunderbolt, or wirelessly.
Source: Dropbox
USB Flash Drives
Small, portable flash memory sticks that plug into any USB port. Lower capacities than HDDs/SSDs but very convenient for transferring files between devices.
SD Cards
Removable flash memory cards used in digital cameras, mobile devices, and other electronics. Provide storage capacities from megabytes to gigabytes.
Optical Discs
CDs, DVDs, and Blu-ray discs are optical media that store up to 700MB, 4.7GB, and 25GB respectively. Read/write speeds are slower than flash drives.
Magnetic Tape
Magnetic tape has been used for decades for archival storage. Very high capacities but slow access times. Used primarily for backups and archiving.
Advantages
Some key advantages of external storage include:
Portability
External storage devices like USB flash drives, external hard drives, and SD cards are highly portable and lightweight (Source). This makes it easy to carry large amounts of data with you and access it from different devices.
Expandable Storage
External storage allows you to expand the storage capacity of your computer or device very easily. If you run out of space on your laptop or phone, you can simply plug in an external drive to increase the storage without having to replace the device itself (Source).
Data Backup
Having an external drive provides a great backup solution to prevent data loss. You can regularly back up important files and documents to external storage for safekeeping (Source).
Disadvantages
External memory storage devices have some drawbacks to consider before using them. One key disadvantage is that they can fail or stop working properly, leading to potential data loss. Being external devices, they are more vulnerable to physical damage from drops, impacts, water exposure, etc. compared to internal storage inside a computer case. According to this article, hard drives aren’t infallible and can malfunction or fail unexpectedly.
Another disadvantage for some types of external storage, like traditional hard disk drives, is slower speeds compared to internal storage options like solid-state drives. The interface used to connect the external device, such as USB or Firewire, can also bottleneck transfer speeds. So if fast data transfer rate is a priority, an external HDD may not be the best choice.
There is also the risk of external storage devices being lost, stolen, or misplaced since they are portable and not securely housed inside a system. Proper encryption and password protection is highly recommended to secure sensitive data stored on external devices that could end up in the wrong hands.
Use Cases
External storage devices have several common use cases that take advantage of their portability, capacity, and persistence. Some of the most popular uses are:
Backing up files – One of the main uses of external storage is to create backups of important files on a computer’s internal drive. Regularly backing up files to an external device protects against data loss if the internal drive fails or is damaged. External drives provide a convenient way to store multiple backups and keep them separate from the source computer.
Transferring data between devices – The detachable nature of external storage makes it very useful for transferring large amounts of data between computers and devices. For example, external drives are commonly used to move photos, videos, project files, and other data between a desktop and laptop computer. High-capacity external drives are also used for backing up data from smartphones, tablets, and other mobile devices.
Expanding storage capacity – External drives can instantly add large amounts of storage space without having to upgrade a computer’s internal drive. This expanded capacity is useful for storing large files like high-resolution photos and videos. External storage also provides overflow space when a main hard drive starts running out of room.
References:
[1] https://www.hp.com/us-en/shop/tech-takes/top-5-uses-for-external-hard-drives
[2] https://www.techtarget.com/searchstorage/definition/external-storage
Hardware Interfaces
There are several common hardware interfaces used for connecting external storage devices to computers and other devices. Some of the most popular interfaces include:
USB
USB (Universal Serial Bus) is one of the most widely used interfaces for connecting external storage devices. USB ports are standard on almost all modern computers and allow connection of devices like external hard drives, flash drives, and CD/DVD drives. Current mainstream versions of USB are USB 3.2 Gen 1 (5 Gbps), USB 3.2 Gen 2 (10 Gbps), and USB 3.2 Gen 2×2 (20 Gbps) (Source).
Thunderbolt
Thunderbolt is a high-speed interface developed by Intel and Apple. It allows connection of external storage devices like RAID arrays and external SSDs. The current version, Thunderbolt 3, provides speeds up to 40 Gbps. Thunderbolt ports are found mainly on Apple computers and some premium Windows PCs (Source).
FireWire
FireWire (also known as IEEE 1394) is a high-speed interface standard used primarily for connecting external hard drives and audio/video equipment. FireWire provides transfer speeds up to 800 Mbps. While less common today, FireWire is still used in some storage devices, professional video cameras, and audio interfaces (Source).
eSATA
eSATA (external Serial ATA) provides a fast external interface for SATA storage devices. eSATA connections support transfer speeds up to 6 Gbps. However, eSATA ports are not commonly available on consumer devices. eSATA is more often used in external hard drive enclosures and RAID systems (Source).
File Systems
The most common file systems for external hard drives and USB flash drives are FAT32, exFAT, NTFS, and HFS+. Here’s an overview of each:
FAT32 ([1], [2]) is supported by Windows and macOS. It has a maximum individual file size of 4GB and maximum partition size of 2TB. It’s a good option for small storage drives.
exFAT ([1], [3]) removes the limitations of FAT32, supporting larger files and partitions. It’s supported on Windows and macOS after Mavericks.
NTFS ([3], [2]) is the default system for Windows. It supports advanced features like permissions and encryption. NTFS drives can only be read on macOS.
HFS+ ([1]) is the default file system for macOS. HFS+ drives can only be read on Windows.
Security
When storing sensitive data on external storage devices like USB drives or external hard drives, it’s important to take measures to secure the data through encryption and access control. Encryption transforms data into unreadable code that requires a password or key to decipher. This protects the contents if the storage device is lost or stolen. Some options for encrypting external drives include BitLocker on Windows, FileVault on Mac, and third party software like Veracrypt. Encryption should be enabled whenever storing financial records, personal documents, or other private information.
Additionally, password protection and physical control of the device also help secure external data. Setting a password on the device prevents unauthorized access if connected to another machine. Physically securing the device in a locked drawer or safe when not in use reduces the risk of theft and data breaches. Proper encryption, passwords, and physical control work together to protect sensitive data stored on external devices.
According to Proton, “if the data you have stored in your external drive is solely for your use, then you should encrypt it, full stop.” Encryption is an essential step for securing sensitive external data.
Lifespan
The lifespan of an external hard drive depends on the type of drive it is. Solid state drives (SSDs) generally last longer than traditional hard disk drives (HDDs). According to this Reddit discussion, the average lifespan of an external HDD is around 3-5 years with regular use. However, SSDs can last over 10 years with normal use. This is because SSDs have no moving parts whereas HDDs use a mechanical arm to read/write data which is more prone to fail over time.
Proper care and maintenance of an external drive can help prolong its lifespan. Avoiding physical shocks, operating at extreme temperatures, and disconnecting without properly ejecting can all reduce the working life of a drive. Regular backups of data to a second device is also recommended in case of unexpected failure.
Conclusion
In summary, external storage devices like USB drives, external hard drives, and memory cards allow users to store data externally and transport it between devices. They provide additional storage capacity beyond a computer’s internal storage. Key benefits include portability, the ability to backup and transfer files, and expandable storage. Downsides can include slower speeds compared to internal storage, potential for data loss or hardware failure, and security vulnerabilities if devices are lost or stolen.
Looking to the future, external storage devices will continue to evolve with new form factors and increased capabilities. Key trends include expanded capacities up to 100TB or more, faster transfer speeds as interfaces improve, built-in security features like encryption, and new technologies like holographic storage. The Internet of Things and edge computing may also impact external storage use cases. But traditional external drives like USB flash drives and portable hard drives will continue meeting basic portable storage needs. Users can expect external storage devices to provide convenient expanded capacity for many years to come.