Gustafson’s law
Beginner
The observation that when you get more helpers, you usually take on a bigger job, so the helpers stay useful.
Novice
, where and are the fractions of time spent on serial and parallel work on the -processor machine. It assumes the job grows with the machine: more processors are used to solve a bigger problem in the same time.
Expert
Fits throughput work whose size grows with the hardware (bigger batches, higher resolution). Amdahl’s law fits a fixed job with a latency target, such as one frame or one query. Pick the one that matches what the spec fixes.