Fastest way to detect number of faces in an image

Question

I know how to detect number of human faces in an image using dlib and opencv in Python. But I want to do it for a lot of images so I want to do it as fast as possible.

1. Will using any other language (like Go) be faster?
2. Is there any other faster way of doing it (any other model or framework or method)?

I am not able to find relevant resources on google (they are mostly on how to do it). I am doing some research before any implementation so I don't have anything to show. But anything in this direction is appreciated.