DomeGuy@lemmy.world 2 days ago
There are four things that matter for transfer speed between storage devices.
- How fast the source reads
- How fast the target writes
- How fast the bits can be moved between them
- What post-write nonsense is done.
USB sticks tend to be flash memory with relatively equal read and write speeds, but the spinning disks in a hard disk drive are noticeably unequal. So, unless the USB is very slow, you’d expect a USB to HDD copy to be slower than either USB to USB or HDD to USB.
You can also be slowed down by antivirus scans, on-disk encryption, search indexing, or even the need to move bits from the USB bus to the HDD controller.