The USB 3.2 Gen 2 header (20 pins) is sometimes refereed to as a Type C header or Type E header, but I can not find any evidence of that being apart of the standard. There is also a 40 pin variant:


What header is used for:

  1. USB 2.0 High-Speed 0.48Gbps
  2. USB 3.2 Gen 1×1 SuperSpeed 5Gbps
  3. USB 3.2 Gen 2×1 SuperSpeed 10Gbps
  4. USB 3.2 Gen 2x2 SuperSpeed 20Gbps
  5. USB4 Gen 3×2 SuperSpeed 40Gbps
  6. USB4 Gen 4 SuperSpeed 80Gbps

and what is the 40 pin connector used for?

  • 2
    If the USB specification says the only difference is the number of pins that must be the only difference. However, the fact they don’t have a diagram of the 40-pin, tells me that it’s not used. None of those except the top two are applicable to either the 20-pin or the 40-pin USB 3.1 Gen 1 (aka USB 3.2 Gen 1)header
    – Ramhound
    Commented Jan 9 at 3:28
  • @Ramhound, Does that mean the bottom 4 items on the list use the USB 3.2 Gen 2 header? (also that document says USB 3.1, could the USB4 standard take advantage of the 40 pins?)
    – Brandon
    Commented Jan 9 at 3:36
  • "Could the USB4 standard take advantage of the 40 pins?" - No; The specification you provided ONLY applies to USB 3.1. USB 4 has its own specifications. All your question can be answered by the USB 4 specification here
    – Ramhound
    Commented Jan 9 at 10:54
  • A grammar nit-pick on the question: "apart of the standard" should say "a part of the standard".
    – abb
    Commented Jan 10 at 2:55

1 Answer 1


The 40-pin header is an extension of the 20-pin count. The only difference between the two is the pin count.

20-pin supports one full feature Type-C port.

The 40-pin header was introduced to support two full feature Type-C ports. See Newnex USB Connector Type Guide.


  • Can the USB 3.2 Gen 2 20 pin header support a USB4 Gen 4 SuperSpeed 80Gbps at full speed or does it require a different header?
    – Brandon
    Commented Jan 9 at 3:48
  • @Brandon you could experiment, but please note USB 3.2 Gen 2 supports USB4 and speed is up to 10Gbps due to limitations of USB 3.2 Gen 2. kensington.com/news/docking-connectivity-blog/…).
    – Full Array
    Commented Jan 9 at 3:58
  • How are you supposed to get an 80Gbps port? I have only seen PCIe cards with it. Is there no header that supports 80Gbps in the standard?
    – Brandon
    Commented Jan 9 at 4:15
  • You should ask that question to the community next. I answered your original question. Please vote up and mark it as answered if you think I did answer your original question..
    – Full Array
    Commented Jan 9 at 4:18
  • Question asked here: superuser.com/q/1824982/401540
    – Brandon
    Commented Jan 9 at 5:14

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