Well, multiple goroutines can run in parallel, which isn't possible in CPython. That's a huge difference right off the bat, even if gc has some work left in opt

Well, multiple goroutines can run in parallel, which isn't possible in CPython. That's a huge difference right off the bat, even if gc has some work left in optimizing the implementation. (As far as non-concurrent code goes, gccgo is very well-optimized, because it's basically piggy-backing on the extensive optimizations of gcc over the decades.)