Actually the most interesting part of the article is not about using GOMAXPROCS, but exactly how using GOMAXPROCS doesn't automagically turn your program into a

Actually the most interesting part of the article is not about using GOMAXPROCS, but exactly how using GOMAXPROCS doesn't automagically turn your program into a parallel one: only a real analysis (helped with the helful profiler) tells you whether you've achieved true parallelism. The author's program wasn't truly parallel until he saw the bottleneck with the global mutex lock. Said differently: concurrency is easy ("just" go func() all the things), parallelism is hard (GOMAXPROCS is not enough, you'll have to go deeper)