While copying from an optical drive can be slow, that is a long time.
What type of disk are copying from and where are you copying to, a hdd or another optical drive. If it's an optical drive then other factors come into it, is it a DL disk, how many files, (not just how much space they occupy) how fast are the drives at reading and writing.
Are they RAM disks, which are typically very slow. DVD-RW are about 60% slower to read and write.