Hi there, the slow file-moving process is determined by loads of possible factors: speed of the computer, speed of the external hard drive, sizes of the files, amount of the files, and USB speed. If you want to speed up the moving process, the easiest way is to use a higher USB version.
As is well-known, there are USB-A, USB-B, and USB-C types. Type A, B, or C of USB only refers to the physical design (Or shape) of the ports and connectors.
USB-A is a flat and rectangular shape. USB-B has multiple designs, but the common shape is a bit squarer. And the design of USB-C is a smaller rectangular with rounded corners.
No matter it's a Type A, B, or C USB, only the USB versions can determine the data transfer speed of the USB cable. All three types of USB ports can run USB versions 1.1, 2.0, 3.0, or 3.1. The higher the USB version is, the faster the speed it brings.
Therefore, you can check the USB port version of your device and the external hard drive and apply a higher one as much as you can.
Hope you good luck!