Librem 14 USB C Port Dual Monitor Capabilities

Hi there,
I am looking into replacing my lenovo x230 with the librem 14.
One thing I don’t want to miss is the easy docking.

Unfortunately I cannot find enough information about the capabilities of the USB C port on the librem 14.

I would like to use a dock like this one (https://www.raidsonic.de/products/adapter_multidocking/multi_docking/index_en.php?we_objectID=6089) to drive two external displays via the one USB-C connection. Does anyone know whether that will work?

The dock description states as requirement for driving two displays: “USB 3.1 Gen2 (10 Gbit/s), DisplayPort Alt Mode and Power Delivery”

In the librem 14 description I am only missing the “Gen2” part which leaves me a bit puzzled.

Also Purism are advertising that it can drive two displays, one via USB-C and one via HDMI, which does not explicitly rule out a chance of success for my plan, but could be implicitly interpreted so :slight_smile:

So is anyone already successfully driving two monitors via some dock through USB-C?
All I can find here in the forum is this negative report.

Thanks for any reports and thoughts,
Dino

OK, so what you are after is Display Port daisy chain and I am sorry, but no, this is not supported and IIRC the reason is that the Intel SOC does not support it. So if you want more than one external screen you need to take the HDMI port as second screen connector.

The non-working HUB you referred to this is unfortunate but sadly also not uncommon with type-C devices I’m afraid. Type-C is still fairly new and many devices do not 100% comply to the standards - this for sure also includes the Librem 14 and the type-C controller chips themselves. These issues have improve a lot during the past 2 years or so but still are not gone and you can find all kinds of reports of things working or not working on this or that laptop / device. A lot of factors come together. With the Hubs in many cases it has to do with power supply and power consumption. I have a bunch of type-C hubs here and pretty much every single one behaves a bit differently. For example I also have one that produces a similar problem like the one in the referenced blog post. But it starts to work if you first plug it to a really powerful PD source and then to a type-C host - something not so straight up with the power negotiation? Since these devices do not have their own debug output very hard to tell what they actually do and what now.

So my piece of advice for type-C peripherals: Buy them with money back guarantee. Chances are it will not work as expected.

Cheers
nicole

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Hi Nicole,
thanks a lot for your reply!
Thank you also for reporting based on actual tests with several docks, that multi-display via a USB-C dock does not work with the Librem 14. This ends my speculation :slight_smile:

However I am not sure whether this really involves DP daisy-chain. The mentioned dock has three display outputs, so the two displays I am after would not be connected in a chain but directly to the dock. But I might be misunderstanding you or not know enough about the technological aspects of how the multi-display function is realized in this dock.

Still I am not sure about Intel SOCs not supporting this. The product reviews in a big online store where no one should buy stuff from show reports of this dock actually working with laptops of several manufacturerers, mostly based on Intel processors.

Dino