What is the speed difference between the front USB and the rear USB of the desktop?

Plug the newly purchased Seagate Backup Plus Drive (USB 3.0 gen1) into the front USB 3.0 Gen1 interface of the desktop (icon is SS) and the rear USB 3.0 Gen1 (icon is SS) interface for copy testing.

The desktop model is DELL Optiplex 7020

Test project:

Copy files from the local desktop hard disk (mechanical hard disk) to Seagate Backup Plus Drive (8TB) through the explorer of Windows 10, with a file type of .mkv and a single file of no less than 6GB; copy testing in the same direction through Robocopy, using 4 threads

It turns out that using the front USB for testing, the highest write speed is 40MB/s (viewed through task manager). And through the post-USB interface for testing, the highest writing speed of 210MB/s.

It can be seen that the gap is quite large, so when using mobile hard drives or external disks, you should try to use the rear USB interface to maximize performance.