1 Reply Latest reply on Oct 24, 2016 11:11 AM by Intel Corporation

    Thunderbolt 40Gbps?


      Hello guys,

      my question is simple: How does Thunderbolt 3 transmit 40Gbps?

      As far as I understand it is bound to PCIe 3.0 with 4 lanes, each of these lanes has a rate of 985MB/s which is 7.880Mbps. So, if each lane has roughly 8Gbps and TB3 uses four of them it should result in around 32Gbps, not 40Gbps.

      Where am I wrong?

      It is not an urgent question, it is just for my understanding.


      Thanks in advance.

        • 1. Re: Thunderbolt 40Gbps?
          Intel Corporation
          This message was posted on behalf of Intel Corporation

          Hello Sorrider,

          In regard to your concern, I did a research and these are the details that I get for you:

          Intel resolved early display quality issues encountered on early hardware through a firmware update in 2011. The interface employs two data channels, each capable of pushing 10 Gb/s in each direction. The solution used one channel for the I/O device and the other for display signaling. Even still, we cite 10 Gb/s as Thunderbolt's official spec, since performance is not additive.

          You can see a clear reference in the image attached as; thunderboltcable_bandwidth_600px.

          Also, you can find more details of Thunderbolt Technology at the following link:


          Thunderbolt™ 3