Storage Devices Flashcards
What is a computers primary memory storage?
Random Access Memory (RAM)
What is the advantage of secondary storage?
It retains its contents when the computer’s power is turned off
What is the disadvantage of secondary storage?
It is not directly accessible to the processor and has slower access speeds
What are some examples of secondary storage?
The computer’s internal hard disk, optical media and solid state disks
How do hard disk work?
A hard disk uses rigid rotating platters coated with magnetic material, iron particles on the disk are polarised to become either north or south state, representing 0 and 1, the disk is divided into tracks in concentric circles, and each track is subdivided into sectors, the disk spins at up to 10,000 RPM, the drive head moves across the disk to access different tracks and sectors, and data is read from or written to the disk as it passes under the drive head
What is a disadvantage of a hard disk?
They are less portable than optical or solid state media
What is a advantage of a hard disk?
They have huge capacities with the newer 3.5 inch disk have capacities of up to 640GB
What are the 3 different formats of optical disks?
Read-only (CD-ROM), recordable (CD-R) and rewritable (CD-RW)
How does an optical disk work?
An optical disk works by using a high powered laser to ‘burn’ sections of its surface, making them less reflective, a laser at a lower power is used to read the disk by shining light onto the surface and a sensor is used to measure the amount of light that is reflected back
In a optical disk what is the parts of the surfaces that have been ‘burned’ called?
Pits
In an optical disk what are the lands that have not been pitted called?
Lands
How much data does a CD-ROM hold?
Around 700MB
How does recordable disk work?
They use a reflective layer with a transparent dye coating that becomes less reflective when it is ‘burned’
How much data does a Blu-ray hold?
Around 50GB
How does a Blu-ray disk hold more data than a CD-ROM
It has smaller pits
What is a advantage of optical storage?
It is very cheap to produce and easy to send through the post for distribution purpose
What is a DISadvantage of a hard disk?
It can however be corrupted or damaged easily by excessive sunl8ight or scratches
How does an solid-state disk (SSD) work?
SSDs store data permanently inside an integrated circuit, typically using flash memory, the flash memory inside an SSD means data is written, transferred, and erased electronically and silently
What is an advantage of a SSD?
They have faster access speeds than hard disks, they consume far less power meaning that for a laptop battery life is extended and they can stay cooler and are less susceptible to damage with no moving parts and are silent in operation, lighter and highly portable
What is an disadvantage of a SSD?
Their capacity is relatively low
What are the 2 kinds of internal memory?
Random access memory (RAM) and read-only memory (ROM)
What is RAM?
Is used to store program and data that are currently being used, it is volatile
What is ROM?
ROM is used to hold information that needs to be permanently in memory, for example the bootstrap loader (the program that starts up as soon as the computer is switched on and cause the OS to be loaded) has to held in ROM
What is ‘virtual servers’?
Cloud-based or private, off site servers that connect a local machine to the files you need via the Internet
What is the advantages of virtual storage?
Reduced hardware costs
Improved reliability and performance
The flexibility to scale the storage requirements up and down as your need change over time
What is the disadvantages of virtual storage?
You will need to rely on a fast internet connection and will have to have a separate backup plan in place your storage provider has a hardware failure and cloud storage can be costly and cloud stoages provisers may result in a loss of funactionality and a comprinsie in control compared the private server
What is the disadvantages of virtual storage?
You will need to rely on a fast internet connection and will have to have a separate backup plan in place your storage provider has a hardware failure and cloud storage can be costly and cloud storage providers may result in a loss of functionality and a compromise in control compared the private server
