Parallel Processing and Multi-core Systems

This lesson explores how modern computers achieve high performance not just by making a single processor faster, but by performing multiple operations simultaneously. You need to understand different forms of parallelism, multi-core architectures, and their limitations.

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Why Parallelism?

There are physical limits to how fast a single processor core can run:

• Increasing clock speed generates more heat, requiring more power and cooling.
• Signals cannot travel faster than the speed of light — shrinking transistors helps but has limits.
• The power wall — beyond a certain point, increasing clock frequency leads to diminishing returns because power consumption rises disproportionately.

The solution: instead of making one core faster, use multiple cores or processing units working in parallel.

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Types of Parallel Processing

1. Instruction-Level Parallelism (ILP)

ILP exploits parallelism within a single instruction stream. The processor identifies instructions that do not depend on each other and executes them simultaneously.