Slow copying speeds from a drive attached to the My Cloud’s USB port is a well known and well discussed issue in this support form. You can use the forum search feature (the magnifying glass icon upper right) to find those other threads.
A few suggested solutions:
Use either the My Cloud Desktop program, the My Cloud Mobile Apps (for iOS or Android) to move/copy files from the USB drive attached to the My Cloud to the Shares on the My Cloud (or vise versa). Or issue a copy/move command using the SSH interface.
Connect the USB drive direct to the computer, connect the computer via Ethernet wire to the same router/gateway/switch/hub that the My Clouds is connected too in order to transfer a large amount of files to the My Cloud.
One possible reason for the slow transfer rate when using Windows File Explorer or Mac Finder, which is made even WORSE if one is connected via Wi-Fi, is the data being copied or moved is flowing from the USB drive, through the My Cloud, then through the user’s computer, then back to the My Cloud to the Share on the My Cloud.
If you haven’t reviewed the following thread its a good starting point for trying to deal with slow copying speeds.
