Gene Amdahl

Gene Amdahl has died. For decades he was, and now will be forever one of the greatest computer technologists of history. The NYTimes has a good obituary. He was one of the primary engineers behind IBM's System/360 which became one of the most successful mainframes ever.

http://www.nytimes.com/2015/11/13/technology/gene-amdahl-pioneer-of-mainframe-computing-dies-at-92.html 

Amdahl's Law is simple yet quite fascinating. It explores the notion of how we think about parallel computation, or even more generally, performing a series of tasks, so there are some relevant considerations for assembly line process and/or people management. It puts a theoretical limit on the speedup we can achieve in a system, and those limits are startlingly low. For example, lets say you have a task, of which 50% is parallelizable (can be processed side by side). Amdahl's Law says it doesn't matter how many workers you have, you can never get a speedup beyond 2x. It makes no difference if you have a thousand or a million workers on a task which is 90% parallelizable: you have have an upper bound on a 10x speedup. It's a formulation of the classic law of diminishing returns, with a very straightforward equation to back it up.