I have two AFP file shares mounted on my OS X laptop. Both AFP shares are on the same OS X server. When I copy files across them, it looks like the files transfers to my machine first and then back up to the server. Is seems like a waste of time. Why can't it transfer it directly without having to down the network and back up?
Filesystems don't know when they're copying files. They know that an application has opened a file and is reading from it, and they know that an application has created another file and is writing to it, but there's no way for the filesystem to know that the new file being written is ultimately intended to be an exact copy of the file being read from.
If you want to transfer a file directly on a server, do something like this: