Yes, goroutines run on separate cores. Go uses an M:N threading model. goroutines (M) which are ready to run are scheduled on a thread pool of POSIX threads (N) which I believe is sized to match the number of cores in the processor. Nothing stops those goroutines from racing on shared memory. However, there is a convention that before accessing some shared memory, goroutines synchronize themselves using channels. ("Do not communicate by sharing memory; instead, share memory by communicating.")
