I am always confused about those USB-C ports without Thunderbolt. It looks like they only support USB 3.1, because the Bus version is 3.1 but it shows 3.2 in the device tree. For the speed it doesn't matter anyway. I just wonder if the advantages of 3.2 can even be used. I don't know any in my use case for now. Especially with only USB 2 devices connected at the moment.
You can ignore the USB 3.1/USB 3.2 difference.
USB 3.0, USB 3.1 gen 1 and USB 3.2 gen 1x1 are all the same (5 Gbps)
USB 3.1 gen 2 and USB 3.2 gen 2x1 are all the same (10 Gbps)
USB 3.2 gen 1x2 (10 Gbps) and USB 3.2 gen 2x2 (20 Gbps) are new to USB 3.2 but Apple Macs do not come with controllers that can do x2.
USB 2.0 is totally separate from USB 3.x. USB 2.0 uses different wires so it doesn't interfere with USB 3.x.
I have two 3.2 Gen 2 Hubs where all ports support 10Gb/s, one is connected to the other and the first one is shown as USB 3 Gen 2 instead of USB 3.2 Gen 2. Very strange.
They are the same brand, the one directly connected to the Mac has two USB-A and two USB-C ports and the other one four USB-C ports.
Some USB hubs have name strings in their device info which System Profiler.app will display. Ignore the name and look at the connection speed info.
All USB-A ports on both of them are orange inside. Does the color stand for 3.2 Gen 2? Or something else?
Some manufactures follow a USB color convention. Some (Apple) do not.
https://www.storagereview.com/news/what-is-usb-c-background-and-overview
Both ports seem to use the same bus, what is even more confusing because it's 5 busses and 5 ports alltogether with the three TB5/USB4 ports. At the moment there is only one TB3 SSD connected and the other two ports are free.
A bus has one or more ports.
Apple Silicon Macs have one Thunderbolt port per Thunderbolt bus (controller). I think they also have one USB port per USB bus (controller) or two USB ports since there is one port for USB 3.x traffic and another port for USB 2.0 traffic.
It looks like that on my M4 Pro Mini:
View attachment 2508962
This looks so confusing. The Sound Blaster is the only thing connected to the second USB-Hub what is hanging on the first Hub, but look like it's connected to the first Hub and the second one is empty. The SSD isn't on any Hub but it looks like that.
A USB hub can be connected to a port of anther USB hub. It's a tree structure with the Mac as the trunk.
The SSD is a USB device. It is connected to a hub which is connected to a USB bus (controller).
The hub may be an external hub or it might be inside the Mac or inside the SSD.
The empty busses only show:
Host Controller Driver: AppleUSBXHCITR
TR is TitanRidge which is an Intel Thunderbolt 3 controller.
XHCI is a USB controller. A Thunderbolt controller may contain a USB controller.
I suppose Apple could use this driver for its USB controllers?
Except the last one, that is showing:
Host Controller Driver: AppleUSBXHCITR
PCI Device ID: 0x15f0
PCI Revision ID: 0x0006
PCI Vendor ID: 0x8086
8086:15f0 is
https://admin.pci-ids.ucw.cz/read/PC/8086/15f0
Maybe this one is inside the TB3 SSD?
The output from the
ioreg
command might be more informative because it includes USB ports that have nothing connected to them.
You can find IORegistryExplorer.app from Apple developer tools. It has a nice UI to view the I/O registry. Then you can look for the USB controllers and hubs and ports.
You can connect/disconnect a USB or Thunderbolt device and the nodes in the IO Registry will appear as green (newly connected) or red (newly disconnected).