Mycloud extremely slow

My Cloud OS 3 Personal & Network Attached Storage My Cloud
2

You are comparing two different values, Megabits per second (Mbps) to Megabytes per second (Mb/s). Not to mention comparing broadband speed vs local network speed. 90 Mbps comes out to be roughly 11.25 MB/s.

See the following discussion on the issue of copying speed to/from the My Cloud:

https://community.wd.com/t/before-you-pack-up-your-wd-and-return-it-lets-talk-about-copying-speeds/91887