Drive Super Slow (~45MB/s)

I’m running a 24T My Book Duo but I’m getting slower speeds than my single hot-swappable 7200rpm SATA drive.
I’ve swapped out both cables and computers. This is my third unit; the first two were also slow but I presumed they were defective.
I have tried various configurations with the cables. The computer has 3.1 Gen 1 and Gen 2, and I’ve tried both. I installed and ran the utility software.
Anyone have any ideas? Am I missing something glaringly obvious? Feel free to tell me I’m a dumb-a$$ because of [thus and such.] As long as you provide a solution.

Hi @scratchy,

Please refer to the below link to check Common Causes and Solutions for Slow Network Data Transfer Speeds: