1.2: MEMORY AND STORAGE 2.0 Flashcards
What is a major disadvantage of SSDs? Give an example.
- expensive, tends to be smaller in capacity than other types.
- For example, a solid-state drive that holds 256 GB might be of a similar cost to a hard disk with several terabytes capacity.
How does power requirement correlate to the efficiency of SSDs?
-require little power, making them ideal for portable devices where battery life is a big consideration.
Considerations for an appropriate type of secondary storage (6) and their relevance.
Cost - cost per gigabyte (GB)?
Capacity - how much data can the medium hold?
Speed (of access) - how quickly can data be transferred to and from the medium?
Portability - how portable is the medium? Does it need to be portable?
Durability - how robust is the medium, and how robust will it need to be?
Reliability - how resilient and long-lasting is the medium?
SPEED:
SSD: fast as there are no moving parts
MAGNETIC: slow due to moving parts
OPTICAL: slow and limited as there are moving parts
CAPACITY:
MAGNETIC: large
SSD: sufficient
OPTICAL: low
COST:
MAGNETIC: cheapest per GB
OPTICAL: cheap for small storage
SSD: expensive
PORTABILITY:
SSD: highly portable and lightweight
OPTICAL: highly portable and light weight
MAGNETIC: internal drives are not portable, external drives are large in size.
RELIABILITY:
SSD: extremely reliable
MAGNETIC: very reliable
OPTICAL: good in the medium term
DURABILITY:
SSD: extremely durable
MAGNETIC: good when not in use, can be affected by magnetic fields and heat
OPTICAL: susceptible to scratches and will degrade over time with exposure to sunlight
what form is data stored in inside of a computer?
-binary form
what is a bit?
the smallest unit of data a computer can use.
what must happen to denary numbers before they can be processed/ used by a computer?
-must be converted into their binary equivalent before a computer can use them.
what is Overflow?
the result of a binary calculation exceeds 8 bits/ the denary value 255
what do you write in a binary overflow error?
00000000
why are overflow errors bad?
-overflow can have serious consequences for the validity of calculations.
through what process are binary numbers multiplied/ divided?
-through a process called shifting.
how do you multiply and divide with binary shifts?
- multiply: shift to the left
- divide: shift to the right
why is hex useful?
-large numbers can be represented using fewer digits.
equation for
sound file size:
sound file size = sample rate x duration (s) x bit depth
equation for:
image file size
image file size = colour depth x resolution (image height (px) x image width (px))
equation for:
text file size
text file size = bits per character x number of characters
explain why computers represent data in binary form:
- Computers consist of transistors / logic circuits/gates.
- Which only have two values: on (1) or off (0)
explain why hexadecimal is used by computer scientists: (2)
- Easier/ faster to convert to and from binary.
- composed of fewer digits: 8 bits are represented by 2 characters which thereby makes it easier for humans to remember and makes it less susceptible to human errors
what is Binary? (2)
what is denary/ decimal?
- Data format that can be represented by electrical voltages,
- which can then be processed by logic gates in the computer
-numbers we use in real life
can denary be processed by the computer?
no
what does the term ‘encoding’ mean?
Converting data into a binary format so that that it can be stored and processed by a computer
what are logic gates?
what do logic gates only process?
what do we use along with it? and for what reason?
- The basic building block of digital computers
- 1s and 0s
- use binary to encode all data
what does the term ‘base’ refer to?
what is the base of binary, denary/decimal and hex?
-number of digits used by a number system
binary = 2 denary = 10 hex = 16
what do the terms ‘most significant bit’ and ‘least significant bit’ refer to?
MSB-leftmost bit of a binary number- column with the largest place value
LSB-furthest right bit in a binary number
what is a possible issue that could be encountered with a right shift?
-an issue with precision occurs where odd numbers are divided since a standard byte cannot represent fractional numbers.
