If you use git and clone the same (or related) repositories in multiple places on a single disk, they can share the hashed object to reduce disk space and/or network usage and increase speed.

One workflow is to git clone mirror the main repo and use that as a shared read-only source of historical references when cloning a new repo. You can also hardlink or reference those objects to save disk space (though some file systems will do that transparently for you).

It feels like this could be done entirely transparently to the user, for a free speed boost but it's not quite there yet and still needs some thought and setup. Some big services use this behind the scenes though so it's presumably robust.

So worth looking into if you are spending time waiting for clones.