1.1.1 Updated

Question 1

How does faster clock speed improve performance? (2)

Answer 1

Gives more cycles per second (1) More instructions are executed per second (1) So the program takes less time to run (1)

Question 2

How does larger cache memory improve performance (2)

Answer 2

More space for data in cache (1) RAM needs to be accessed less frequently (1) Accessing cache is quicker than accessing RAM (1)

Question 3

Features of Von Neumann Architecture?

Answer 3

Single control unit (1) Single ALU (1) Follows FDE cycle (1) Data and instructions are stored in the same memory (1)

Question 4

Assembly mnemonics that change the contents of PC

Answer 4

BRA. BRP. BRZ

Question 5

Improving performance of a computer 9 marker

Answer 5

Replace CPU with faster CPU. add more/faster RAM. add a graphics card. update OS. Install a lighter weight OS. defragment the hard disk. check for viruses and ransomware. Newer CPU has faster clock speed and more cache and more cores so executes more instructions. More RAM means more programs can be opened simultaneously. Graphics card speeds up rendering graphics. Higher performance hardware costs more. Running an antivirus is free/low cost. Defragmenting HDD is free and it should be performed.

Question 6

Advantage of flash storage rather than magnetic

Answer 6

Has no moving parts so it’s less likely to be damaged. It consumes less power so battery needs recharging less often. It’s unaffected by magnetic fields which could lead to data loss. Faster access speed so photos can quickly be browsed.

Question 7

Assembly mnemonics that change the contents of the accumulator

Answer 7

LDA. SUB. ADD. INP.

Question 8

Describe what is meant by RAM (2)

Answer 8

Random Access Memory (1) A form of primary memory (1) used to hold data and programs in use (1). It’s volatile (1)

Question 9

Why is OS stored in ROM (2)

Answer 9

Software will not need updating (1) Non-volatile so OS won’t be lost when it’s turned off (1) It can’t be overwritten (1)

Question 10

Advantage of RISC over CISC (2)

Answer 10

Costs less to produce (1) Requires less cooling built-in (1) It can run off smaller battery (1) Has fewer instructions than CISC processors (1) Simpler circuit design (1) Fewer transistors (1)

Question 11

Disadvantage of cloud storage (1)

Answer 11

Vulnerable to hacking (1) Relies on an internet connection (1) Relies on company servers (1)

Question 12

Describe why a supercomputer is useful (2)

Answer 12

CPUs can work in parallel (1) on the same problem (1)

Question 13

One feature not part of Von Neumann architecture which contemporary CPUs may have to improve performance (2)

Answer 13

2 separate ares of memory (1) one for instructions and one for data (1). Different set of buses (1) one for instructions and one for data (1). Multiple cores (1) where each core acts as a processing unit (1).

Question 14

Discuss the differences between assembly code and high-level languages (9)

Answer 14

Assembly code uses mnemonics to represent machine code. High level languages are closer to English language. More lines of assembly code is needed to perform the same task as a few lines of high-level code. Assembly is specific to the instruction set of a given processor. High-level languages are not architecture specific. Assembly is very efficient. Assembly allows direct control of hardware and how memory is used via addressing modes.

Question 15

Explain why RISC processors have a better battery life than CISC (3)

Answer 15

RICS has a smaller instruction set (1) so it requires less complex circuitry (1) so less power is used (1)

Question 16

Define the term multicore processor (2)

Answer 16

More than one processing unit in a single processor (1) which can independently process instructions at the same time (1)

Question 17

What is meant by optical media (2)

Answer 17

Read/written using a laser (1) Read/written onto a reflective surface (1) Data is stored using pits and lands (1) Eg. Blu-ray and CD

Question 18

Describe what happens during the Fetch stage (4)

Answer 18

Data is copied from PC to MAR (1) PC is incremented by 1 (1) Data in MAR is passed onto Address Bus (1) Read signal is sent onto the control bus (1) RAM copies the data from that location by the address bus onto the data bus (1) Data on the data bus is passed into the MDR (1) Data is copied from the MDR to the CIR (1)

Question 19

Describe 2 ways that an OS manages physical memory (4)

Answer 19

Paging (1) blocks of memory of fixed size (1) Segmentation (1) blocks of memory of variable size (1)

Question 20

Explain a benefit of memory management to the user (2)

Answer 20

Security - doesn’t let programs access memory reserved for other programs (2). Multitasking - allows multiple programs to run at once (2)

Question 21

Describe how virtual memory allows a user to run programs (2)

Answer 21

Currently unneeded pages moved from memory to secondary storage (1) to create room in memory (1) Pages are moved back to memory when needed (1)

Question 22

Describe a difference between CISC and RISC (2)

Answer 22

Some instructions in CISC will rarely get used. In RISC instructions are used regularly (2) In assembly for CISC a statement that takes one mnemonic may take multiple mnemonics in RISC (2) Compilers for RISC need to be more complex than CISC compilers (2) CISC architecture has complex circuitry so it’s more expensive to manufacture. RISC architecture has simple circuitry so it’s cheaper to manufacture (2)