[SOLVED] gang powered USB hubs?

[DLes]

I have a seven-port powered USB hub. Works fine. I need a few more powered USB ports, and I'm reluctant to use up the second of the (only two!) USB ports on my M1 Mac to host a second one. Larger numbered powered hubs are rare and very expensive. Can I get a second seven-port powered hub and just gang it to the first, giving me 13 powered USB ports? My understanding is that a port will support 127 connections, so I'm thinking it's probably OK, but ... ?

 

[sizzling]

Yes. Done this before on PC, assume a Mac will also be ok.

 

[USAFRet]

Larger numbered powered hubs are rare and very expensive

I have this 13 port:
https://www.amazon.com/gp/product/B00HL7Z46K

$25, almost 7 years old.

 

[DLes]

Thank you all. Good to know about experience with ganging, and that Sabrent 13-port one somehow escaped my attention. Good deal! I note that in the Amazon piece for that it specifically says "Add up to 127 Devices by Daisy-Chaining Multiple Hubs . Works for me!

 

[Inthrutheoutdoor]

Add up to 127 Devices by Daisy-Chaining Multiple Hubs

Regardless of the machine or the hub, I would NEVA, EVA, even attempt to connect anywhere near that many devices in a daisy chain, even if the USB spec says it is theoretically possible...

But in your case of using self-powered hubs, using 2 of them together should not cause any issues AFAIK

 

[DLes]

Regardless of the machine or the hub, I would NEVA, EVA, even attempt to connect anywhere near that many devices in a daisy chain, even if the USB spec says it is theoretically possible...

But in your case of using self-powered hubs, using 2 of them together should not cause any issues AFAIK

For a generic non-powered hub, that's certainly true. But the point is that we're talking about powered hubs. That's what that quote from Amazon was referring to.

 

[Paperdoc]

Yes, with powered Hubs the power limit issue is not really a problem. The real limit then becomes the fact that ALL of the devices in this group are sharing ONE USB host port's data rate capacity. In a lot of situations this is not any real problem, both because each device is a low-data-rate one (e.g., keyboard, mouse) and because you never actually use ALL of them simultaneously. So you never saturate the host port's ability, and never experience any noticeable lags.

 

[DLes]

I think the point was that you CAN daisy chain 127 devices. Not that they're going to work that well. You CAN tie 127 sprinklers to a hose bib, and not much is going to come out of each one. Exactly right that the issue is the shared data rate. In my case, there is little competition for data rate. I have a scanner, some backup disks, a camera port, and an optical drive, but they're almost never used simultaneously. The rest are low data rate devices. Power sharing on an unpowered hub is more serious, because if the power drops too low, things simply won't work. If the data rate drops too low, things will just go slower.