1.1.2 Types of Processor Exam Questions
Paper 1 · Computer Systems · 9 past paper questions · 31 marks
Exam questions for 1.1.2 Types of processor
9 OCR past paper questions (31 marks) with mark schemes
Answer each question, reveal the mark scheme, then award yourself marks. Scores and answers are saved in this browser so you can see which topics need more work.
Download Questions & Mark Scheme (PDF)Past paper questions
- Question 1H446/01 · June 20171 mark
An architect firm specialises in designing skyscrapers. The firm uses high end computers with high performance CPUs, GPUs and large amounts of RAM. Give one use the firm might have for GPUs.
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To render models of proposed buildings Run CAD software Run modelling calculations Any example sensible to scenario (1 mark)Mark yourself: how many marks did you get?/ 1 - Question 2H446/012 marks
Define the term 'multicore processor'.
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More than one processing unit in a (single) processor ...which can independently process instructions at the same time (2 marks - 1 per bullet) Too many candidates defined a multi core processor as 'a processor with multiple cores' this is not creditworthy at this level of study. Candidates must demonstrate their understanding of a core being a processing unit within a processor.Mark yourself: how many marks did you get?/ 2 - Question 3H446/01 · June 202212 marks
A charity has several desktop computers in their office that use a CISC processor. They are considering buying mobile devices for their staff to use when they are not in the office. Discuss whether these mobile devices should use the same CISC processors that are used in their desktop computers or if they should use a RISC processor instead. You should include the following in your answer: the difference between each processor type, the suitability of each processor type for mobile devices.
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Mark Band 3-High Level (9-12 marks): The candidate demonstrates a thorough knowledge and understanding of both CISC and RISC. The material is generally accurate and detailed. The candidate is able to apply their knowledge and understanding directly and consistently to the context provided. Evidence/examples will be explicitly relevant to the explanation. The candidate provides a thorough discussion which is well balanced. AO1: CISC is a complex instruction set - the traditional approach to processor design. Lots of instructions available although some instructions in CISC will rarely get used. RISC is a reduced instruction set - a smaller number of instructions available, several instructions can be combined to perform the same tasks as CISC processors. RISC instructions are used regularly. RISC has fewer transistors/less complex circuitry whereas CISC integrated circuits are more expensive/complicated. RISC instructions take one cycle whereas CISC may take several. RISC can only do complex things by combining multiple instructions whereas CISC is done in one line. Compilers for RISC need to be more complex than compilers for CISC. AO2: CISC processors would run the same software as the desktop machines. Would be less power efficient and require larger battery and cooling mechanisms. More expensive to purchase. RISC processor requires software to be written specifically for it (cannot use CISC instructions). More power efficient and so requires less/no cooling and smaller battery/longer battery life. RISC devices may require greater RAM as programs tend to be larger than their CISC equivalents. AO3: Mobile use of CISC would save money on software and increase compatibility but cost more to purchase and be physically larger (heat sink/larger battery) and/or have a shorter battery life. RISC would require investment in software but be cheaper to purchase and give a better performance out of the office (lighter/longer battery life). Some compatibility issues may be reduced with emulators and translators. (12 marks - levels of response question)Mark yourself: how many marks did you get?/ 12 - Question 4H446/012 marks
OCRSystems are designing a new CPU for a computer system that will be used for video rendering. Part of the video rendering process is when the video is exported. This is when the computer combines all of the separate video elements together to form the final video. An important design consideration is whether OCRSystems use a CISC processor type or a RISC processor type. Describe one difference between a CISC processor and a RISC processor.
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CISC has a larger instruction set / RISC has a smaller instruction set CISC is difficult to pipeline / RISC is easier to pipeline CISC tends to have more addressing modes / RISC tends to have fewer addressing modes CISC instructions may take multiple clock cycles to execute / RISC instructions take one clock cycle to execute CISC has complex circuitry/more transistors / RISC has less complex/simple circuitry CISC uses less RAM / RISC uses more RAM (2 marks - 1 per valid difference, mark in pairs) Accept any other valid pointsMark yourself: how many marks did you get?/ 2 - Question 5H446/012 marks
CPUs can be designed to take a Complex Instruction Set Computer (CISC) or a Reduced Instruction Set Computer (RISC) approach. Describe one difference between CISC and RISC.
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Some instructions in CISC will rarely get used... In RISC instructions are used regularly In assembly for CISC, a statement that takes one mnemonic... (may) take multiple mnemonics in RISC Compilers for RISC need to be more complex... than compilers for CISC CISC architecture has complex circuitry and is therefore more expensive to manufacture... RISC architecture has simple circuitry minimising manufacture cost More than one clock cycle for each instruction in CISC... one clock cycle for each instruction in RISC (2 marks - 1 per bullet, max 2)Mark yourself: how many marks did you get?/ 2 - Question 6H446/012 marks
A company produces digital photo frames (i.e. photo frames that display digital photographs). The photo frame has a RISC processor. Describe one advantage to the company of using a RISC processor, rather than a CISC processor.
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Costs less to design/produce Requires less cooling to be built in (If battery powered) can run off smaller battery Has fewer instructions than other (CISC) processors Simpler (circuit/hardware) design/manufacture Fewer transistors (2 marks - 1 per bullet, max 2, 1 max from 'because' group) Some candidates did not gain credit because the advantage stated was not specific to the company, as the question asked. Candidates should be reminded to read the question carefully.Mark yourself: how many marks did you get?/ 2 - Question 7H446/013 marks
Describe what is meant by a co-processor and give an example of its use.
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A secondary processor that performs specialized tasks / Works alongside the main CPU / Offloads specific computations Examples: GPU for graphics processing / FPU for floating point calculations / Cryptographic processor for encryption (3 marks)Mark yourself: how many marks did you get?/ 3 - Question 8H446/013 marks
Explain what is meant by parallel processing and describe one benefit of using it.
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Multiple processors/cores executing instructions simultaneously / Tasks divided across multiple processing units / Benefit: Faster execution of parallelizable tasks / Better throughput / Can handle larger workloads (3 marks)Mark yourself: how many marks did you get?/ 3 - Question 9H446/014 marks
Describe the purpose of a GPU and explain why it is suited to its task.
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Purpose: Processing graphics/rendering images / Performing parallel computations Why suited: Many simple cores / Optimized for parallel operations / Can process multiple pixels simultaneously / SIMD architecture / High memory bandwidth (4 marks)Mark yourself: how many marks did you get?/ 4
- 1RISC vs CISC: Simple/1 cycle per instruction vs Complex/multiple cycles
- 2GPU uses SIMD: Single Instruction Multiple Data - ideal for graphics/ML
- 3Multicore limitation: Doubling cores doesn't double performance - software must be written for it
- 4Parallel processing benefits: Faster parallelisable tasks, better multitasking
- 5Parallel processing drawbacks: Not all tasks parallelisable, increased debugging complexity
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