# Daisey-chaining USB hubs? **URL:** \ **Category:** Factual Questions\ **Created:** [September 9, 2010, 7:43pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214 "2010-09-09T19:43:39Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![KlondikeGeoff](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@KlondikeGeoff](https://boards.straightdope.com/u/KlondikeGeoff)\ **Post date:** [September 9, 2010, 7:43pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/1 "2010-09-09T19:43:39Z")
My 8-socket powered USB hub is now full, as well as the four on the back of my desktop box, and I need more (don’t have all these USB devices running at the same time). Any problem adding another powered hub to the existing one to provide more sockets? ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [September 9, 2010, 8:00pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/2 "2010-09-09T20:00:23Z")
You can daisy-chain them. USB is designed for daisy-chained hubs. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [September 9, 2010, 8:03pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/3 "2010-09-09T20:03:53Z")
Anyone else hear a melodic _Got to keep the USBs on the path_? (Or do I just have brain damage?) ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [September 9, 2010, 8:11pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/4 "2010-09-09T20:11:50Z")
You can daisy chain them as much as you like, but you do have the limit of 127 USB devices per USB root hub. Note that many of the ports on your computer may come from the same root hub (chances are the four at the back are all on one). Granted, 127 is a lot of USB devices, but if you really want to go hog wild, that’s your limit. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [September 9, 2010, 8:15pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/5 "2010-09-09T20:15:44Z")
> [@engineer\_comp\_geek](#): > > You can daisy chain them as much as you like, but you do have the limit of 127 USB devices per USB root hub. Note that many of the ports on your computer may come from the same root hub (chances are the four at the back are all on one). > > Granted, 127 is a lot of USB devices, but if you really want to go hog wild, that’s your limit. Just in case I wanted to go for a record, what defines a root hub? My board has pins for two ports on the front of the case and four sets of pins for ports on the rear of the case (right now I have two-port brackets plugged into each). Is each set of pins a root hub or could they be extensions of the same one? How would one tell? ---
**Author:** ![zagloba](https://avatars.discourse-cdn.com/v4/letter/z/977dab/32.png) [@zagloba](https://boards.straightdope.com/u/zagloba)\ **Post date:** [September 9, 2010, 8:37pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/6 "2010-09-09T20:37:34Z")
The limit of 127 includes hubs. There are some boxes with that connect with USB which internally consist of a hub and 2 or more devices. Each internal hub and device counts towards the 127 limit. I think you can find the number of actual root hubs in Device Manager, but I don’t have time to look it up just now. I think most laptops have only one. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [September 9, 2010, 9:23pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/7 "2010-09-09T21:23:29Z")
> [@Rhythmdvl](#): > > Anyone else hear a melodic _Got to keep the USBs on the path_? > > (Or do I just have brain damage?) No, but every time I see the thread title, I misread it as “Disney chanting USB hubs” and feature a string of them singing “Heigh ho, heigh ho, it’s off to work we go.” 😃 ---
**Author:** ![KlondikeGeoff](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@KlondikeGeoff](https://boards.straightdope.com/u/KlondikeGeoff)\ **Post date:** [September 9, 2010, 9:47pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/8 "2010-09-09T21:47:52Z")
> [@engineer\_comp\_geek](#): > > You can daisy chain them as much as you like, but you do have the limit of 127 USB devices per USB root hub. Note that many of the ports on your computer may come from the same root hub (chances are the four at the back are all on one). I can just picture a chain of 127 of 'em. Would look like a boa constrictor, I think. Thanks all, glad to know I can do this. I was concerned my entire computer might go up in a cloud of smoke if I tried it. As per usual, can always depend upon the great people in the Dope to fight my ignorance. Oh yeah, damn, I misspelled “daisy” in the thread title. Well, I read that Hemingway could not spell well either. ---
**Author:** ![JoelUpchurch](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@JoelUpchurch](https://boards.straightdope.com/u/JoelUpchurch)\ **Post date:** [September 9, 2010, 9:50pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/9 "2010-09-09T21:50:00Z")
Where did you get an 8 port USB hub? All the hubs I’ve seen were 3-port or 7-port hubs. As near as I can tell the popular USB hub chips have 4 ports and the 7 port hubs have 2 chips with one chip daisy chained to the first chip. Since I haven’t looked in a couple of years, I checked again and found a 13 port hub from USBGEAR. I remember back in the old days, there were problems when you mixed USB 1.1 and 2.0 devices on the same hub, since the whole hub would degrade to 1.1 speeds, but I don’t think current hubs have that problem. There also were some devices that wouldn’t work with a hub at all or with some hubs and not others.Back in the really old days they were USB devices that wouldn’t work if they were plugged into a computer with a non-intel chipset. I think the most usb devices I plugged into one computer was around 30 for a burn in computer. I used to have a program that would show all the usb devices on the system with their hierarchy, including the hubs. with that program, I could see that there were 2 chips in the hub. IIRC, there was a limit to the number of hubs you could daisy chain together, but it was a fairly large number like 8 or something. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [September 9, 2010, 10:26pm UTC](https://boards.straightdope.com/t/daisey-chaining-usb-hubs/553214/10 "2010-09-09T22:26:25Z")
> [@engineer\_comp\_geek](#): > > You can daisy chain them as much as you like… Sometimes; Microsoft Speaks: > [@](#): > > [More Than Five USB Hubs in a Chain Are Not Supported](http://support.microsoft.com/kb/226308) > If you have a properly enumerated Universal Serial Bus (USB) hub connected to your Windows 2000-based computer and you add five more hubs connected in a chain, the last hub may not work properly. Windows 2000 does not support USB hubs more than five deep. > > Five hubs deep is the limitation in the USB specification. It is not a limitation in Windows 2000.