Amdahl's Law Calculator

Find the maximum speedup from parallelizing part of a task.

Speedup (x) 4.706

Max possible speedup (x) 10

Formula: speedup = 1 / ((1 - p) + p / s)

Step-by-step with your numbers:

1. Values used:

2. Parallel fraction = 0.9

3. Processors = 8

5. Speedup = 4.706x

6. Max possible speedup = 10x

Did we solve your problem today?

Amdahl's law shows how the serial part of a program limits parallel speedup.

The math behind it

speedup = 1 / ((1 - p) + p / s). Even infinite processors cap speedup at 1 / (1 - p).

90% parallel on 8 cores gives about 4.7x; the ceiling is 10x.

Why diminishing returns?

The serial fraction never speeds up, so it dominates as you add cores.