Amdahl’s Law
Published: October 4, 2024
Amdahl’s Law explains the limits of how much you can speed up a system by improving part of it. It says that even if you make one part of a system much faster, the total improvement depends on how much time that part originally took.
Here’s a breakdown:
- If 60% of the system can be made super fast (almost instant), 40% of the time is still spent on the other parts.
- So, the total speedup is limited by that 40%.
- The formula for speedup is:
Speedup = 1 / (1 – fraction improved)
Example:
- Imagine 60% of a task can be sped up to take no time. That leaves 40% of the task unchanged.
- Using Amdahl’s Law:
Speedup = 1 / 0.4 = 2.5×
No matter how fast you make that 60%, the overall speedup can only be 2.5 times faster.
It shows the diminishing returns of making only part of a system faster.