Overview
Amdahl's Law is most commonly used in parallel computing to predict the maximum speedup when using multiple processors. It states that the speedup is limited by the 'serial' portion of the task that cannot be parallelized.
The Formula
Speedup = 1 / [(1 - P) + (P / N)]
- P: The proportion of the task that can be parallelized.
- N: The number of processors.
Key Insight
Even if you have an infinite number of processors, the speedup can never exceed 1 / (1 - P). If 10% of a program is serial, the maximum speedup is 10x, no matter how many cores you add.