Does Thunderbolt 1 provide USB (3.0) functionality? Or in other words: Is Thunderbolt 1 compatible with USB (3.0)?

I have a MacBook Pro 13'', Early 2011 (MacBookPro8,1) and a Laptop Docking Station (Sabrent DS-RICA), which only has a USB 3.0 B input. I would like to connect the two, but not directly via USB since said MPB has only USB 2.0 and I'm getting hard delays on the external screen via such a USB 2.0 connection.

So I'm thinking about connecting said docking station to the Thunderbolt 1 port of my MBP via an Thunderbolt 1 to USB 3.0 adapter (e.g. this pricy thing). But I'm not sure if this will do the job, because I've heard that Thunderbolt 1 does not transmit data in a way for a USB device to understand, even with this adapter... Now I'd like to check that info with the knowledge of this great community, thanks!


No, there is no USB functionality at all in Thunderbolt 1. However, it is not necessary to have USB functionality inside Thunderbolt for this to work!

The USB functionality is actually inside the Kanex adapter, you've linked. It contains a real USB controller, such as one you would find inside a laptop or PC. These controllers usually attach to a PCI(e) bus - which is exactly what a Thunderbolt port provides (i.e. a kind of extended PCIe bus).

This means that using this adapter, it is indeed possible to connect your MacBook Pro and the Sabrent docking station. It will work just as if your computer had a USB 3.0 port originally.

Similarly there's no gigabit ethernet protocol inside Thunderbolt 1 as such. Instead a real gigabit ethernet controller is inside the Kanex adapter, and this is what "translates" between the PCIe (provided by Thunderbolt 1) and ethernet (where you can connect to a network).


Does Thunderbolt 1 provide USB (3.0) functionality?

No. Thunderbolt 1 does not provide any USB functionality.

Thunderbolt 1 and 2 provide only two protocols: PCIe 2.0 and DisplayPort 1.1a and 2.0 respectively. Thunderbolt 3 is (currently) the only one that supports PCIe 3.0, DisplayPort 1.2 (two streams), USB 3.1 gen 2, and power delivery.

  • Thank you, you answered my question clearly and swiftly (so quick!). Just for the sake of completeness: I reckon that Thunderbolt 1/2 doesn't support USB 2.0 either, right? – CJLM Nov 30 '18 at 11:48
  • No USB support at all until Thunderbolt 3. – Allan Nov 30 '18 at 11:49
  • This is a really strange adapter, then...?! – CJLM Nov 30 '18 at 11:52
  • See this post for a detailed explanation of what PCIe is in Thunderbolt. – Allan Nov 30 '18 at 11:59
  • Your post explains quite a lot, thank you! You're basically saying there that TB port acts as "extension" of the bus and the TB adapter one can buy (ethernet or USB), acts as the corresponding hardware (e.g. ethernet card?), which translates the signal from "PCI language" to the corresponding cable's "language". (This is handy for Apple, since the sell a "slim" laptop and lots of adapters!) What I don't get, is why this is only one way. I see that the translation is "lossy" and cannot be reverted; so a TB cable always needs to be plugged "directly" into a PCI board, i.e. a computer, right? – CJLM Nov 30 '18 at 15:30

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