USB 3.0 or PCIe?


I’m considering getting the uconsole with cm4. But am wondering if there are any add on boards that leverages the USB3 or the PCIe capabilities?

Look for expansion cards on this forum, someon has made a couple including usb

Most seems to be USB2.0 based. Maybe i missed it, but I haven’t come across one that is USB3… If I’m not mistaken, the pi4 supports USB3. The on board USB-A connector is also 2.0. Wondering if there is a reason why a USB3 port wasn’t implemented on the onboard connector….

The USB3 pins on the CM4 are not connected through the adapter board. So the main board is limited to the USB2. The main board was designed for a CM3 unit.

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As far as I know, the SoC on the Raspberry Pi 4 and related boards (400, CM4) does not have USB 3.0 but it offers a PCIe lane. The Pi4 and 400 have a separate interface chip that uses that PCIe lane for the USB 3 ports on those boards. An extension board for the uConsole would need a chip like that to offer the same.


The PCIe interface on the CM4 adapterboad is not connected (see scemetic on git), this means you can not use this on a expansion card in the uconsole unless a different adapter card is designed and made to work white it.

Does anyone know what was the reason not to expose the PCIe lanes on the adapter board? Since that seems to be the only way to achive IO speeds above USB2.0 on the CM4, i’m guessing there must have been a reason not to include it.

The main board was originally slated for the cm3’s SODIMM form factor and features. They were omitted because they didn’t exist at time of design.

I agree with this… ^^ … but… like the pi5… i feel like a new adapter board with the external FPC connector would have been cool… or a single usb-c

Totally agree, from everything I have inferred reading and looking at the schematics, it would require a redesign on the motherboard side or some hardware “hacks” to open up access to the pci-e/usb3 bus. I wouldn’t put it past the community to engineer some sort of clever solution someday there are a lot of super capable people on here.

I also don’t think it’s completely out of the line to think clockwork pi would eventually engineer a replacement main board with the mezzanine connectors vs the sodimm configuration and open up the full pin out of the cm4+.

I am certainly going to be so looking forward to those lanes being open. Looking at CM4 and eventually CM5, I would think that exposing those functions via the modularity of the uconsole is a huge win. I’m really looking forward to some smart people in the community to be able to do this. Or maybe of clockworkpi would take that on to expose the lanes. :sweat_smile: