Gene Amdahl, Pioneer of Mainframe Computing, Dies at 92

[Kevin Burton]

Mildly off topic but I know that some of us were fans....

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

> Gene Amdahl, a trailblazer in the design of IBM’s mainframe computers, which became the central nervous system for businesses large and small throughout the world, died on Tuesday at a nursing home in Palo Alto, Calif. He was 92.

And for posterity's sake:

https://en.wikipedia.org/wiki/Amdahl%27s_law

Amdahl's law is often used in parallel computing to predict the theoretical speedup when using multiple processors. For example, if a program needs 20 hours using a single processor core, and a particular part of the program which takes one hour to execute cannot be parallelized, while the remaining 19 hours (p = 95%) of execution time can be parallelized, then regardless of how many processors are devoted to a parallelized execution of this program, the minimum execution time cannot be less than that critical one hour. Hence, the theoretical speedup is limited to at most 20 times (1/(1 − p) = 20). For this reason parallel computing is relevant only for a low number of processors and very parallelizable programs.

[Lifey]

 I was a fan and 92 gives 12.5 speedup.