Copying Data from one external drive to another

I have never tested or compared but I believe that the speed will be the same. The Finder copy is just a user-interface-friendly way of entering the commands in terminal.

You can get a sense of the speed or time required with some rough calculations.

For instance, if you have a modern Mac with Thunderbolt ports, and the external drives are SSDs, you can expect something like 500-1000 MB/s. But the copy must go through the Mac so the effective speed might be 250-500 MB/s. So to copy 250 GB would be ~ 1000 seconds, or about 20 minutes.

If instead you are using external mechanical drives, those will be closer to ~ 100 MB/s. So the same copy could take 1-2 hours.

Many factors come into play here, but these are examples of ways you can guess what it will take.

To add a bit to @steve626's excellent reply to your post, there would be little difference in transfer speeds with either app as the Mac's processor is doing most of the "heavy lifting" during the data transfer. Then it would be the port types on both devices, and then the external drive types (SSD or HDD).

worx25 wrote:

Thanks to both replies. If I understand it correctly the amount of RAM or the size/speed of the internal SSD are not significant factors for this specific process but the processor is. So then a Mac Mini with an M2 Pro processor would copy faster, all other factors being equal or close to equal.

The port and external device speeds would be the limiting factors.