SLR2-1.1: Multi-core and parallel systems Flashcards
(15 cards)
What is meant by multicore systems?
A single chip containing two or more independent processing units
What can each core do in a multicore system?
Each core can fetch, decode and execute its own instructions
What does CMPS stand for?
Chip Multiprocessors
How are chip multiprocessors (CMPS) used?
Manufactures integrate cores onto a single physical chip known as a chip multiprocessor
What are the two types of multiple cores?
- Dual-core processor: A CMP with two cores
- Quad-core processor: A CMP with four cores
What are some limitations of multi-core processors?
- Performance doesn’t scale linearly
- Overheads with inter-core communications
- Not all programs can use multiple cores efficiently
What does performance doesn’t scale linearly mean?
Doubling the number of cores doesn’t double the performance
What does overheads with inter- core communications mean?
Time an resources and needed for cores to communicate with each other- this can reduce efficiency
What does not all programs can use multiple cores efficiently mean?
Some software is not designed to take advantage of all cores -limiting performance gains
What is parallel processing?
The processing of a programs instructions by dividing them between multiple processors or processor cores
What are some examples of parallel processing?
1) Multi-core processors
2) Dividing tasks
3) SIMD
4) Pipelining
5) Concurrency and parallelism
What are some limitations of parallel processing?
- Dependant on the task being carried out
- Software must support parallel processing
*Some tasks or programs cannot be parallelised
What does dependant on the task being carried out mean?
Not all tasks can be easily split into independent parts to run
What does software must support parallel processing mean?
The software must be written or designed to take advantage of parallel execution
What is does some tasks or programs cannot be parallelised mean?
It limits the benefit of using multiple processors/cores
