[frostirosti]

Amdahl's law is not misleading. Amdahl's law shows the speed up under a fixed problem size. Gustafson simple showed that since we parallelized an aspect of a problem, we can solve larger problems with the time saved. Amdahl's law is the max for fixed problem sizes.

[zzzcpan]

The misleading part is how it is used. As things change, theoretical speed up of the solution becomes irrelevant, and problems also change.

[frostirosti]

Reevaluating Amdahl's Law.

http://www.johngustafson.net/pubs/pub13/amdahl.pdf

[dnautics]

wow even this is a bit hard to parse (and I work with John!)

Basically, Gustafson's law says, "yeah but really what you're going to do with massively parallel computing is you're going to run more copies of the same program, which has a linear scaling factor".