Hi. I’m looking at the framework boards for the mini pc/home server scenario, like a bare-bones platform. Given that Intel SoC from the 11th Gen include a couple Thunderbolt lanes - could those, in theory, be used to connect PCIe cards?
I’m having a bit of a hard time understanding the details of USB4 subsystem as per TigerLake Datasheet, where it mentions PCIe Root Ports on the block diagram. I’d appreciate if somebody could clarify whether the idea is impossible.
eGPU enclosures exist, so I’d say it’s possible
Thunderbolt 3 and above support pcie over a usb-c port.
Usb4 can optionally support the same pcie over a usb-c port.
The AMD based FW13 and FW16 usb4 ports support pcie over a usb-c.
2 of the ports are usb4 capable.
You can connect thunderbolt 3 devices to usb4 ports, and they tend to work.
Thanks for confirming. I’ve read a bit more about usb4/tbt3, e.g. how eGPU or fast external storage enclosures are made, and the necessary part is the controller IC on the device side, like JHL7440.
My original intent was about these inexpensive OCP-sized network cards, to be able to slap them to a mini PC, which generally lack PCIe slots except M.2. So, before over complicating things with tunneling pcie over usb4, I should probably at least verify if they work on non tunneled PCIe and try to design an m.2-to-ocp breakout board.
At least my connectx2 and 3 cards worked just fine with all my egpu boards, so did the intel x540 and aqc113 and that ancient broadcom one, at least before the drivers got removed from linux.
They also all worked when I supplied just 5v to the 12v bus which I found a pleasant surprise.
If you just need fast usb ethernet, realtek just released an usb3.2 to 10Gbit chipset that is pretty nice. Mine can do 8Gbit over a 10Gbit usb connection and only draws 1.8W
Thanks, that’s already a promising set of tests. Regarding the voltage rails - I’ve found this note, although the observation is opposite - they supplied 12v into the 5v rail on an OCP to PCIe adapter.
Also interesting. Last year I’ve checked, there were only 2.5G and 5G ethernet dongles. Now I wonder what would be the CPU usage on the 10G-over-USB, to handle all the USB transfers, polling, lack of offloading… It’s still usb down there, right?
Supplying higher voltages definitely has a bigger chance of spectacular failiure than supplying lower ones XD. I mainly tried 5v because one of my egpu enclosures has a usb-c power input which tires to get 12v but in the case of the framework all it gets is 5v and jet the nics worked (the x540 with it’s 15W power draw got a bit close to the limit for my liking but I would be pretty fine running the connectx or the aquantia on 5v if I had to).
Yeah it’s very new, basically the bigger brother of the 5gbit one. Same as for the 5Gbit no mainline linux drivers unfortunately but the out of tree ones do work relatively well in my not so extended testing. I did not notice anything particularly heavy cpu wise but I do run a 7840u, loading that up is not the easiest task and it is just 10Gbit. Offloading doesn’t really seem all that necessary for just 10Gbit these days.