windows or linux?
how many hubs?
Windows 3 hubs, but i have only 7 HDD connected.
I have total 30 USB ports to 30 hdd
I found the limit is something associated with cpu/mobo, here are more reference data point for you guys:
ASUS PRIME Z490-A LGA 1200 Z490
Intel Core i9-10850K
Connected 23 usb drives with no issue, I ran out of disks to try higher number.
Lenovo M83 with i3-4330
Tops out at 12 drives, any additional will be totally ignored.