Transfer speeds between two USB connected SSDs slower than benchmarking results

[Gwendolini]

Hi,

I recently bought the 512GB MyPassport SSD and copied an FCP X project onto it.

For backup purposes I wanted to employ a 1TB Samsung SSD in a USB 3.0 enclosure.

When testing both with Blackmagic Speed Test, they get more than 200 MB/s write/read speeds.

Both are connected to the Satechi USB-C to 2xUSB-A hub (with power through and HDMI) adapter, but when using Finder or CarbonCopyCloner to copy data between them, it has a speed of 5120/1800 MB/s (<3MB/s).

I tried reconnecting, I tried formatting (the 1TB SSD), I tried copying from MacBook to SSD 1 or SSD 2 (which went with 200MB/s). Maybe I should **** them up a little?


Anyone have an answer for that?

 

[Mike Boreham]

Have you seen this thread?

https://forums.macrumors.com/threads/two-external-usb-drives.2020631/

You really need the fully powered OWC or Caldigit hubs to do this reliably at full speed.