Amdahl's Law
August 01, 2020
Let’s say that you want to speed up 75% of your system’s execution time by three times. What is the overall speedup of the whole system? There’s a formula to solve this problem. It’s called Amdahl’s law and can be formulated as follows.
Where
- is the maximum speedup of the system
- is part of the system that is improved
- is the speedup of
If you speed up 75% if your system’s execution time by three times, the overall speedup of the whole system will be
Amdahl’s law has few important implications:
- As approaches infinity, approaches zero. This means that no matter how far you optimize a system, the overall speedup is always limited by the part of the system that doesn’t benefit from the improvement ().
- You should make the common case fast.