Parallel Speedup Calculator
Estimate ideal parallel speedup using Amdahl’s law.
Your inputs
Calculation results
Formula & assumptions
Speedup = 1/[(1−p)+p/workers]; ignores coordination and scheduling overhead.
Values use the specified units. Calculations use floating-point arithmetic. Check input measurements and formula assumptions before applying the result.
Compare your scenarios
Save up to five results to compare changes side by side. Scenarios stay in this tab until you clear or reload it.
Using Parallel Speedup Calculator
Estimate ideal parallel speedup using Amdahl’s law.
- Enter parallelizable work, workers, serial duration using the units printed under each field.
- Choose Calculate, or enable live updates. Review the result labels and formula assumptions.
- Save scenarios to compare up to five variations, then copy the report or download JSON or CSV.
Example
Parallelizable work: 95 percent Workers: 8 workers Serial duration: 100 seconds Ideal speedup: 5.9259259 Ideal parallel duration · seconds: 16.875 Worker efficiency · percent: 74.074074
Questions & answers
What does Parallel Speedup Calculator calculate?
Estimate ideal parallel speedup using Amdahl’s law.
Which units should I enter?
Parallelizable work uses percent. Workers uses workers. Serial duration uses seconds. Convert values to these units before calculating.
Which formula does it use?
Speedup = 1/[(1−p)+p/workers]; ignores coordination and scheduling overhead.
What does the included example show?
Parallelizable work: 95 percent; Workers: 8 workers; Serial duration: 100 seconds. Result: Ideal speedup = 5.9259259; Ideal parallel duration · seconds = 16.875; Worker efficiency · percent = 74.074074.
Can I compare different settings?
Yes. Save a scenario, change the inputs and save another result. Up to five scenarios are compared in this tab; they disappear when you reload or leave.
Can I export the calculation?
Copy the JSON report or download JSON and CSV with inputs, result labels and numeric values. Processing uses local JavaScript; no calculation request is sent to our server. Displayed values use up to 10 significant digits; exports retain JavaScript numeric precision.
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