What is it?
Performance is limited to the non-speedup portion of the program
Why is it useful?
Suppose a program runs in 100 seconds on a machine.
- Multiply operations responsible for 80 seconds.
How much do we have to improve the speed of multiplication to get a 4x speedup?
Multiplication needs to improve 16x to become 5s.
Note that 20s is not improved however, only multplication is improved.
5 times faster -> impossible no matter how fast we improve our system.
20 + X, X always > 0.