Laws of Software Engineering · Law
Law
Amdahl's Law
Adding more processors only helps with the parts of the work that can run in parallel.
How to use it. Find the part of the work that has to run in order. That part sets your speed limit. If 20% of the work is sequential, you cannot go faster than 5x, however many processors you add.
How it gets misused. People quote it to argue against parallel work entirely. The law sets a limit on the gain. It does not say the gain is worthless.
Related
-
Law
Gustafson's Law
If your problem grows when you add more processors, you can get more speed than Amdahl suggests.
-
Law
Little's Law
Things sitting in the system = how often they arrive × how long they stay.