Are you cloning or imagimg?
Is it to an external or internal drive?
If an external drive, is it USB1 or USB2?
How large is the drive it's copying from?
It does sound like too long - unless you're using an external drive running at USB1 speed.
Surface Pro (2017) vs Surface Pro 4
20 groundbreaking 3D animation technologies coming to Siggraph 2017
iPad Pro 12.9 vs Surface Pro 5
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.