Storage
Characteristics of Backing Storage
- Backing storage: long-term storage used to store data, files, and programs when not in use e.g.:
- hard disk drives (HDD)
- solid-state drives (SSD)
- USB flash drives
- optical discs (CDs, DVDs)
- Backing storage is typically slower than internal memory but has a larger capacity
- It is non-volatile, meaning it retains data when the computer is powered off
Differences between Backing Storage & Internal Memory
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Function |
Long-term storage of files, programs, and data |
Temporary storage of data and essential instructions while the computer is running |
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Examples |
HDD, SSD, USB flash drives, optical discs (CDs, DVDs) |
RAM, ROM |
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Access Speed |
Slower |
Faster |
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Capacity |
Larger |
Smaller |
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Volatility |
Non-volatile (retains data when powered off) |
RAM: volatile, ROM: non-volatile |
Storage Media
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Magnetic Drives |
Hard disks, Magnetic tape |
Long-term data storage, backup, and archiving |
High capacity, low cost per GB |
Slower access time, moving parts, susceptible to magnets |
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Optical Discs |
CD, DVD, Blu-ray |
Data storage, audio, video, and software distribution |
Portable, durable, low cost |
Limited capacity, susceptible to scratches |
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Solid-State Media |
Memory cards (SD, xD, CFast), USB Drives, Solid State Drives |
Fast data storage for portable devices and modern computers |
Fast access time, no moving parts |
More expensive, limited write cycles |
Worked example
Give two error messages that may appear when trying to save to a CFast solid-state memory card.
[2]
Two of:
Medium is full [1]
Corrupt card [1]
Write error [1]
Card error [1]
Card not initialised [1]
Virus found on the card [1]
Device not recognised [1]
Storage Devices
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Magnetic Drive |
Long-term data storage, backup, and archiving |
Magnetic |
High capacity (10TB), low cost per GB |
Slower access time, moving parts, susceptible to magnets |
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Fixed Magnetic Hard Drive |
General-purpose storage in computers and servers |
Magnetic Hard Disk |
Large storage capacity (5TB), relatively fast |
Moving parts, vulnerable to physical damage |
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Portable Magnetic Hard Drive |
External storage for data transfer and backup |
Magnetic Hard Disk |
Portable (5TB), large storage capacity |
Slower than SSDs, vulnerable to physical damage |
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Magnetic Tape Drives |
Backup and archiving, especially for large volumes of data |
Magnetic Tape |
High storage capacity (10TB), low cost |
Slow access time, sequential access |
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CD |
Audio and data storage, software distribution |
CD |
Affordable, widely compatible |
Low capacity (700MB), susceptible to scratches |
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DVD |
Higher capacity storage for data, video, and software distribution |
DVD |
Higher capacity than CD (8.5GB), affordable |
Susceptible to scratches, lower capacity than Blu-ray |
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Blu-ray |
High-definition video and high capacity data storage |
Blu-ray |
High capacity (50GB), high-resolution video storage |
More expensive, and requires specific hardware |
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Fixed Solid-State Drive (SSD) |
Fast internal storage for modern computers |
Solid-State |
Fast access time, no moving parts, high capacity (30TB) |
More expensive, limited write cycles |
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Portable SSD |
External storage for fast data transfer and backup |
Solid-State |
Fast access time, portable, no moving parts, high capacity (2TB) |
More expensive, limited write cycles |
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Pen Drive |
Portable data storage and transfer for various devices |
Solid-State |
Small size, fast read/write speeds, high capacity (1TB) |
Limited capacity compared to other storage devices |
Worked example
A program collects a large amount of data and this could be stored using either a fixed solid-state drive (SSD) or cloud storage.
a. Describe four advantages to the school of using cloud storage rather than using the SSD
[4]
Four of:
The cloud has greater storage capacity [1]
The data could be sent directly to/from the cloud from any computer/device [1]
Storage capacity can be increased without adding additional physical devices [1]
Many people can share the data [1]
The school would only pay for the storage used [1]
There is an automatic backup of data [1]
b. Describe three disadvantages to the school of using cloud storage rather than using the SSD
[3]
Three of:
More security issues as multiple copies of the data are stored [1]
The school loses control over the storage of the data [1]
Cloud storage has an ongoing cost [1]
Users must have a reliable internet connection to store data [1]
Users must have an internet connection to access data [1]
