Wrong. Goroutines are not simply coroutines.
GOMAXPROCS defaults to number of cores.
GOMAXPROCS defaults to number of cores.
Prove it by replacing Sleep in your example with some number crunching, and show how it scales with the number of cores in your CPU.
Running the following code.
https://play.golang.org/p/k_rRxNAyb0i
I can assure you that go runs across all processors by default.
https://docs.google.com/document/d/1At2Ls5_fhJQ59kDK2DFVhFu3...