How many usb hubs can you daisychain?

Hardware Hub Other Hardware
1

I must know

2

Completely depends on the USB port itself and what you connect to it.

3

what if I daisychain a 10 port usb hub with 10, 10 port usb hubs. then on each of those hubs I place 10 more usb hubs. then I connect 10 gaming mice to each of the remaining usb ports.

4

I believe the limit is 127 usb devices

5

USB is only as fast as its slowest device when it comes to hubs. Honestly would not recomend daisy chaining USB hubs, or using USB Hubs for that matter if you can help it.

6

What if I sold my soul to satan in exchange for daisychaining being a efficient way of using several peripherals at once.

7

If that were the case then I suppose anything is possible

8

Troll or real answer and why?

9

Genuine answer, as to why I imagine it has something to do with the chipset but I'm sure someone with a better understanding could explain it properly

10

@J3llyf1sh is right. USB is limited to 127 devices per controller. Any time you have a USB controller, it doesn't matter which ports the devices are attached to. The bus (as in Universal Serial BUS) is one single unit and everything is done by the controller. So, if you're using the motherboard chipset you can plug each device into separate USB ports on the motherboard, or you can plug one hub into one port on the motherboard, attach the same devices, and get basically the same performance. The thing to keep in mind here is that you will need to provide power for all the attached devices, and each hub counts as a device.. Also, the bandwidth limit quoted by USB standards isn't a device limit, it is a shared bus limit. So for USB 2.0, each device doesn't max out at 480 MB/s, all the devices combined max out at 480 MB/s.

So yes, 10 hubs with 10 ports each would work. 127-10 would leave you with 117 device you could hook up to a that chain, so long as the hubs were powered and all the devices got sufficient power. Your data transfer rates would be probably be crap though.

1 Like
11

Troll thread turned useful!

12

I'm a man of the people, hahaha

13

Is there any particular reason for it being 127 USB devices?
My guess would be that USB peripherals on the same controller assigned a 7 digit binary number each (giving a total of 128 possibilities)?

14

im gona go with 42

15

Yes, as far as I understand it: 7-bit address with the controller taking one address, so 127 remaining addresses to be assigned.