For example, Python using the GMP library --
http://shootout.alioth.debian.org/u64/program.php?test=pidig...
http://shootout.alioth.debian.org/u64/program.php?test=pidig...
http://shootout.alioth.debian.org/u64/program.php?test=pidig...
http://shootout.alioth.debian.org/u64/program.php?test=pidig...
Which doesn't matter much if Go's machine code/runtime is inefficient or if Python libs are written in C in the first place whereas Go's are written in Go.