What I want to achieve is to connect a Mini Pcie Express device to a thunderbolt (1 / 2) port. I have looked around and such connector does not seem to exist, so as a computer engineer I went looking on how I could design my own PCB for that.

From the information I gathered so far, it seems that Pcie should work straight through Thunderbolt. I have seem the specification for mPcie and of the minidisplay port(which should be the same as thunderbolt).

MiniDisplayPort https://i.sstatic.net/BszqB.jpg

MiniPcie https://i.sstatic.net/W1YC0.jpg

Through my readings I found out that Pern0 and Perp0 are data receiving pairs and Petn0 and Petp0 are data transmiting pairs.

I was unable to find decent specifications regarding the thunderbolt end point, my big question then is, in which lane in the display port cable should I put Per and Pet, and if there would be a need to supply information to Pin 2(hot plug), 4(config1), 6(config2), 20(pwr out) in the mini display port cable. Also, is there anything else that would have to be supplied to the Pcie ?

There are a few thunderbolt docks, with PSUs, etc that achieve what I'm trying here, but they are way too expensive and overkill to my problem. I am also trying to this to learn more about PCB design.

  • \$\begingroup\$ Trust me, you won't make something cheaper than the available docks. If you want to learn PCB design as part of such a project, you are throwing yourself into the middle of the ocean without a floatation device. PCIe and Thunderbolt are hard. \$\endgroup\$ Commented Jun 5, 2018 at 14:26

1 Answer 1


You can not connect a PCIe directly to a Thunderbolt port, it requires a controller chip at each end. See the description from Wikipedia below.

Thunderbolt controllers multiplex one or more individual data lanes from connected PCIe and DisplayPort devices for transmission via two duplex Thunderbolt lanes, then de-multiplex them for use by PCIe and DisplayPort devices on the other end.

The picture below from an Intel Thunderbolt Technology Brief shows the connectivity described above.

enter image description here

  • \$\begingroup\$ Thanks for the info. Seems the project is hopeless then. \$\endgroup\$ Commented Jun 5, 2018 at 14:30

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