Amdahl’s Law

The main idea is that when we speed up one part of a system, the effect on the overall system performance depends on both how significant this part was and how much it sped up.

Suppose some part of the system requires a fraction $\alpha$ α of this time, and that we improve its performance by a factor of $k$. So speedup $S$ (部分性能优化对整体的提速倍数):

\[S = \frac{1}{(1-\alpha) + 2/k},\]

When,

\[\alpha = 部分耗时占比\] \[k = 部分性能提速倍数\]

References

• Book: Computer Systems: A Programmer’s Perspective, Third Edition (2016)