Adding a USB-port hub on a TB3 Dock: Is it possible?

[coolajami]

Hi
I'm wondering if anyone has tried to add a USB-port hub or a TB3 or TB4 hub on a TB3 Dock and what his/her experience.

I'm using a Caldigit TS3+ Dock and I'm in desperate need of more USB Ports.

I am thinking to use the USB-C or the 2nd TB3 port for adding an unpowered USB-C port hub like the Kensington USB-C 4 port Hub(CH1000) with the hope that it would add 4 more port, however the transfer speed would be about 1GB per port and it would not be able to power energy hungry devices (I think maximum output power per port would be about 900mA ).

Alternative I was thinking the addition of a TB3 or TB4 hub on the second TB3 port of the TS3+ Dock, like the Caldigit Element Hub or the OWC Thunderbolt Hub, but I think that may be more risky not to work, as these hubs are designed to be connected directly to the computer.

If anyone tried any of the above, could he/she kindly share his/her experience?

 

[joevt]

The TB3 port of the CalDigit TS3+ has the best 10 Gbps USB performance on the dock. Use it for 10 Gbps USB docks and devices if you're not daisy chaining another Thunderbolt device. The other 10 Gbps USB port of the CalDigit is only 8 Gbps so it's not great for 10 Gbps devices but should do equally well for 5 Gbps. The 5 Gbps ports have slightly less 5 Gbps performance than the 8 and 10 Gbps ports.

USB Type C ports are supposed to be able to do 3A. 900 mA is for USB 3.0.

The Kensington is only USB 5 Gbps. Their product page is garbage and there seems to be a newer version of the CH1000 with two USB-C ports.
https://www.kensington.com/p/produc...s/usb-connectivity/ch1000-usb-c-4-port-hub-4/
https://www.kensington.com/p/produc...ivity/kensington-ch1000-usb-c-4-port-hub/?r=1

5 Gbps means 4 Gbps of data, 1 Gbps per port if you tried to do transfers to all 4 ports at the same time in the same direction. Usually you'll only be using one device at a time so you'll get a full 4 Gbps to that one device (≈460 MB/s). If you're reading from that device then you can send a full 4 Gbps to another device since each direction uses different wires.

As for Thunderbolt 4 Hubs, they can be connected to Thunderbolt 3 devices and they'll work at full performance. Thunderbolt 4 devices have full compatibility starting with Big Sur. Catalina and earlier will have issues (no hot plug - the TB4 hub needs to be connected before boot). Thunderbolt 4 hubs come with a power supply that must be used but it has the benefit of giving the USB ports more power.

Consider the CalDigit Element Hub - it has 3 Thunderbolt 4 ports (15W each) and 4 type A ports (7.5W each) - all ports can do 10 Gbps USB. All 7 ports share a single 10 Gbps USB connection so to get more performance than that would require connecting a Thunderbolt device or using the USB ports of the TS3+. The TS3+ has four USB controllers: two 4 Gbps controllers each with 4 ports, one 8 Gbps controller with two ports - one of them is limited to 4 Gbps, one 10 Gbps controller total with one port - the Thunderbolt port. While a Thunderbolt 4 hub only has one USB controller with one port and two four port hubs chained together to that port).
https://www.caldigit.com/thunderbolt-4-element-hub/
https://www.caldigit.com/ts3-plus-interface-bandwidth-allocation-and-diagram/

 

[coolajami]

The TB3 port of the CalDigit TS3+ has the best 10 Gbps USB performance on the dock. Use it for 10 Gbps USB docks and devices if you're not daisy chaining another Thunderbolt device. The other 10 Gbps USB port of the CalDigit is only 8 Gbps so it's not great for 10 Gbps devices but should do equally well for 5 Gbps. The 5 Gbps ports have slightly less 5 Gbps performance than the 8 and 10 Gbps ports.

USB Type C ports are supposed to be able to do 3A. 900 mA is for USB 3.0.

The Kensington is only USB 5 Gbps. Their product page is garbage and there seems to be a newer version of the CH1000 with two USB-C ports.
https://www.kensington.com/p/produc...s/usb-connectivity/ch1000-usb-c-4-port-hub-4/
https://www.kensington.com/p/produc...ivity/kensington-ch1000-usb-c-4-port-hub/?r=1

5 Gbps means 4 Gbps of data, 1 Gbps per port if you tried to do transfers to all 4 ports at the same time in the same direction. Usually you'll only be using one device at a time so you'll get a full 4 Gbps to that one device (≈460 MB/s). If you're reading from that device then you can send a full 4 Gbps to another device since each direction uses different wires.

As for Thunderbolt 4 Hubs, they can be connected to Thunderbolt 3 devices and they'll work at full performance. Thunderbolt 4 devices have full compatibility starting with Big Sur. Catalina and earlier will have issues (no hot plug - the TB4 hub needs to be connected before boot). Thunderbolt 4 hubs come with a power supply that must be used but it has the benefit of giving the USB ports more power.

Consider the CalDigit Element Hub - it has 3 Thunderbolt 4 ports (15W each) and 4 type A ports (7.5W each) - all ports can do 10 Gbps USB. All 7 ports share a single 10 Gbps USB connection so to get more performance than that would require connecting a Thunderbolt device or using the USB ports of the TS3+. The TS3+ has four USB controllers: two 4 Gbps controllers each with 4 ports, one 8 Gbps controller with two ports - one of them is limited to 4 Gbps, one 10 Gbps controller total with one port - the Thunderbolt port. While a Thunderbolt 4 hub only has one USB controller with one port and two four port hubs chained together to that port).
https://www.caldigit.com/thunderbolt-4-element-hub/
https://www.caldigit.com/ts3-plus-interface-bandwidth-allocation-and-diagram/

Thanks for the info. I was thinking the Kensington 4 usb port (2 USB-C, 2 USB-A) as a cheap option to expand the connectivity of the Caldigit TS3+. The Caldigit Element hub seems the ideal solution but it is too expensive.

Bus-powered hubs seems to be an alternative cheap solution, but I'm unsure what they support in terms of power. From what I've read in several websites, the bus-powered hubs would be unable to provide satisfactory power to devices like the an Apple Super Drive regardless if the connection is USB-A 3.0 or USB-C. That seems logical to me as the 3A output of the USB-C would have to split over 4 ports.

I was mainly wondering if someone had some fist-hand experience of using this setup: TB3+ -> Bus-powered USB hub.