USB Device Tree Viewer

Hello everyone.

I wanted to share this software I found randomly, which can be used to see more easily the number of root host controller your computer has, as well as the detail of the connected devices (drives, hubs, etc.) Works on windows, not sure about the equivalent for linux/mac, any contribution appreciated (i’ll edit this post).

It’s useful for those of you who do USB farming (few drives). I still recommend going to SAS for easier scaling.

Few points to remember regarding usb farming on the top of my mind :

  • The maximum number of devices (drives, hubs, others) on 1 controller is theoretically 128, usually a lot less depending on the controller and its hardware implementation
  • Each hub takes at least 1 drive from the controller
  • USB3 hubs take 2 drives from the controller (one for usb2 and one for usb3)
  • Most usb3 hub have a 4 port limit, if yours is a 7 port it’s usually two controllers (4+3)
  • There’s a maximum number of nested hubs (4 levels?)
  • USB2 is fine for harvesting, but you don’t want to be doing anything else at the same time (including transfering plots)
  • Plugging a usb2 device will force the controller into usb2 mode which subsequently limits all the usb3 devices plugged in the same controller
  • Most computers have 1 or 2 root host controller max

I’ve been using this, an many other of his command line tools, for years.

Thumbs up from me.


Great tool to have thanks