1. Dr. S. Pradeep Narayanan, Assistant Professor,
Senior Grade I, SENSE, VIT Chennai.
ECE3004 –
Computer Organization and
Architecture
2. ➢ Processor level parallelism - Dependency,
➢ Flynn taxonomy,
➢ Memory organization for Multiprocessors
system,
➢ Symmetric Multiprocessor,
➢ Cache Coherence and The MESI Protocol.
Module 7 : Multiprocessors
3. – It is the technique which provides simultaneous data processing for the purpose
of increasing the computational speed of a computer system.
– parallel can be achieved by multiple functional unit that perform identical or
different operations simultaneously.
- In computers, parallel processing is the processing of program instructions by
dividing them among multiple processors with the objective of running a
program in less time.
- The simultaneous use of more than one CPU to execute a program. Ideally,
parallel processing makes a program run faster because there are more engines
(CPUs) running it.
In practice, it is often difficult to divide a program in such a way that separate
CPUs can execute different portions without interfering with each other.
Parallel Processing
4. ➢ Single Instruction, Single Data Stream - SISD
➢ Single Instruction, Multiple Data Stream - SIMD
➢ Multiple Instruction, Single Data Stream - MISD
➢ Multiple Instruction, Multiple Data Stream- MIMD
Multiple Processor
Organization
Flynn’s Taxonomy is a classification of a
computer architectures:
5. ✓ Single processor.
✓ Single instruction stream.
✓ Data stored in single memory.
✓ Uni-processor.
Single Instruction, Single
Data Stream - SISD
6. ▪ Single machine instruction.
▪ Controls simultaneous execution.
▪ Number of processing elements.
▪ Lockstep basis.
▪ Each processing element has associated data
memory.
▪ Each instruction executed on different set of
data by different processors.
▪ Vector and array processors.
Single Instruction, Multiple
Data Stream - SIMD
7. ✓ Sequence of data.
✓ Transmitted to set of processors.
✓ Each processor executes different instruction
sequence.
✓ Never been implemented.
Multiple Instruction, Single
Data Stream - MISD
8. Multiple Instruction,
Multiple Data Stream - MISD
✓ Set of processors.
✓ Simultaneously execute different instruction
sequences.
✓ Different sets of data.
✓ SMPs, clusters and NUMA systems.
