XPS 13 9343, mDP/TB3

That connector is solely Mini DisplayPort.  The Thunderbolt 1 and 2 specs used the same physical connector as Mini DisplayPort, but neither version of Thunderbolt was implemented on the XPS 13 9343.  Every Thunderbolt 1 and 2 port is Mini DisplayPort, but not every Mini DisplayPort connector is Thunderbolt 1 or 2.  But Thunderbolt 3 uses the same physical connector as USB-C, not Mini DisplayPort, and that first appeared on the XPS 13 9350.  And here again, although every Thunderbolt 3 connector is USB-C, not every USB-C connector supports Thunderbolt 3.

So no, you can't use a Thunderbolt dock, and no external peripheral will add any Thunderbolt version support to that system.

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@cr0cop wrote:

Thank you for the feedback.  I too have the same xps 9343 and need thunderbolt 2 or 3 for an audio interface card that I want to get (apollo twin).  Is there a way to upgrade my xps 9343 to thunderbolt 3 or 2?  Thanks in advance

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Unfortunately no.  The existing Mini-DisplayPort output only has a GPU output wired to it.  TB2 or TB3 would require PCIe lanes to be wired to it, and the Thunderbolt controller chip to run the port, both of which would require a completely different motherboard.  You'd be better off selling the 9343 and buying a used 9350 or better.