How many USB hubs can you daisy-chain to a single port and what will happen if you connect too many?

Risk , 6 months ago

Forget daisy-chaining. I gave up on finding a single decent USB hub, let alone connecting them together.

ares35 , 6 months ago

i have a number of clients with anker powered usb3 hubs. no issues from any of them, and one of those is my.. uh.. 'most difficult' one. if he had a problem, i would know about it

seaQueue , 6 months ago

+1, powered USB3 hubs have worked fine for me as well. Keep them away from any 2.4GHz transceivers though, I’ve had issues with RF noise from them wrecking wireless mouse/keyboard signals.

Risk , 6 months ago

Huh, that’s interesting. That might be exactly the cause of the issue I was having with them (plugging in 2.4Ghz keyboards and mice into them).

seaQueue , 6 months ago

I worked around that by plugging in a usb2 extension cable that came with something I bought and placing the 2.4ghz transceiver maybe 2-3’ away from the hub. Same deal with the mouse and keyboard, they need to be a reasonable distance (some # of inches) away from USB 3 signals.

Risk , 6 months ago

Gunna have to experiment with this, however my PC is set up next to our sofa so the distances might not work out.

seaQueue , 6 months ago

I had a hub on my desk next to my monitor so I just ran the extension up the back of the monitor and fixed it in place near the top edge. That was enough distance (maybe 18-20in now that I think about it) to resolve the interference. If you play around a bit you might find that even 10in is enough distance. Try a USB 2 extension cable too, that’ll keep v3 signalling at a distance.

12bitmisfit , 6 months ago

5 hubs deep and 127 devices per usb controller (not port)

To confuse this more many usb3 or newer controllers won’t handle more than 32 devices.

Now add to that most 7 port usb hubs are actually 2x 4 port hubs.

You may be starting to see why it is so hard to definitively say if a certain usb setup will work or not without testing the actual hardware.

Side note, a lot of usb devices even count as 2 devices due to hw encryption chips, like wd external hard drives.

bladerunnerspider , 6 months ago

There is an LTT video on this subject if you care to look for it.

JTskulk , 6 months ago

I don’t know about Daisy chaining them, but I found that the limit for usb3 is 16 devices. I was using 2 hubs and the integrated ports at the time.

Manzas , 6 months ago (edited 2 months ago)

One port Edit: The fuck did I mean

SpaceNoodle , 6 months ago

To rule them all

Hjalamanger , 6 months ago

According to some other answer here you could be able to have 32 devices but some devices register as two different devices, therefore you can only have 16

actionjbone , 6 months ago

Theoretically, there’s a 127 device max.

In practice, it depends on each vendor’s hardware implementation.

lauha , 6 months ago

Hubs can only go 5 levels deep daisy chained

fuckwit_mcbumcrumble , 6 months ago

Windows will even notify you of exactly this limitation.

From the thunderbolt port on my laptop, to my dock, to my monitor, to my big ass hub was 1 too many hops. Obviously somewhere along there were some hubs that weren’t obvious to the naked eye.

Shurimal , 6 months ago

Obviously somewhere along there were some hubs that weren’t obvious to the naked eye.

Probably the port on your laptop was on a hub built onto the mobo. If my understanding is right that's how USB ports usually are connected: controller->hub->ports. If you open up device manager and go to USB controllers you'll see several root hubs and hubs even when you have no external hubs or docks connected.

lauha , 6 months ago

Yes, of the multiport hubs have a subhubs already