Why does Windows 10 assign different port numbers to the same USB port when plugging in 3.0 vs. 2.0 device?












0















If I plug in a USB 2.0 Storage Device into one of the 3.0 ports of my Windows 10 desktop, its descriptor says that it is plugged in to Hub: 1 Port: 1
Every 2.0 device plugged into this same port will always get this same hub and port number.



However, plugging in a USB 3.0 device, the port numbers are always bigger than 10. So, a USB 3.0 device plugged into the same port will get Hub: 1 Port: 16. This behavior is consistent through all of the USB 3.0 devices I've plugged in.



Why is there a difference in the port number designation of USB 2.0 and 3.0 devices? There is no difference when 2.0 and 3.0's are plugged into a USB 2.0 port.



One reason I thought of was that different controller settings / circuits are used in order to enable 3.0 functionality, and therefore a different port is assigned.










share|improve this question



























    0















    If I plug in a USB 2.0 Storage Device into one of the 3.0 ports of my Windows 10 desktop, its descriptor says that it is plugged in to Hub: 1 Port: 1
    Every 2.0 device plugged into this same port will always get this same hub and port number.



    However, plugging in a USB 3.0 device, the port numbers are always bigger than 10. So, a USB 3.0 device plugged into the same port will get Hub: 1 Port: 16. This behavior is consistent through all of the USB 3.0 devices I've plugged in.



    Why is there a difference in the port number designation of USB 2.0 and 3.0 devices? There is no difference when 2.0 and 3.0's are plugged into a USB 2.0 port.



    One reason I thought of was that different controller settings / circuits are used in order to enable 3.0 functionality, and therefore a different port is assigned.










    share|improve this question

























      0












      0








      0








      If I plug in a USB 2.0 Storage Device into one of the 3.0 ports of my Windows 10 desktop, its descriptor says that it is plugged in to Hub: 1 Port: 1
      Every 2.0 device plugged into this same port will always get this same hub and port number.



      However, plugging in a USB 3.0 device, the port numbers are always bigger than 10. So, a USB 3.0 device plugged into the same port will get Hub: 1 Port: 16. This behavior is consistent through all of the USB 3.0 devices I've plugged in.



      Why is there a difference in the port number designation of USB 2.0 and 3.0 devices? There is no difference when 2.0 and 3.0's are plugged into a USB 2.0 port.



      One reason I thought of was that different controller settings / circuits are used in order to enable 3.0 functionality, and therefore a different port is assigned.










      share|improve this question














      If I plug in a USB 2.0 Storage Device into one of the 3.0 ports of my Windows 10 desktop, its descriptor says that it is plugged in to Hub: 1 Port: 1
      Every 2.0 device plugged into this same port will always get this same hub and port number.



      However, plugging in a USB 3.0 device, the port numbers are always bigger than 10. So, a USB 3.0 device plugged into the same port will get Hub: 1 Port: 16. This behavior is consistent through all of the USB 3.0 devices I've plugged in.



      Why is there a difference in the port number designation of USB 2.0 and 3.0 devices? There is no difference when 2.0 and 3.0's are plugged into a USB 2.0 port.



      One reason I thought of was that different controller settings / circuits are used in order to enable 3.0 functionality, and therefore a different port is assigned.







      usb






      share|improve this question













      share|improve this question











      share|improve this question




      share|improve this question










      asked Jan 8 at 10:03









      ZimanoZimano

      19110




      19110






















          1 Answer
          1






          active

          oldest

          votes


















          0















          One reason I thought of was that different controller settings / circuits are used in order to enable 3.0 functionality, and therefore a different port is assigned.




          Yes, that's very common on older motherboards. If I know correctly, the same ports are wired through a multiplexer (mux) to two USB controllers at once – an EHCI controller for 1.x/2.x and XHCI for 3.x – and therefore each port is actually two. Of course they're still only routed to one controller at a time, but can be instantly rerouted to the other after their speed is determined.



          If you switch Windows Device Manager to "View by connection" mode, you'll see that the devices even show up under different controllers in the device tree.






          share|improve this answer























            Your Answer








            StackExchange.ready(function() {
            var channelOptions = {
            tags: "".split(" "),
            id: "3"
            };
            initTagRenderer("".split(" "), "".split(" "), channelOptions);

            StackExchange.using("externalEditor", function() {
            // Have to fire editor after snippets, if snippets enabled
            if (StackExchange.settings.snippets.snippetsEnabled) {
            StackExchange.using("snippets", function() {
            createEditor();
            });
            }
            else {
            createEditor();
            }
            });

            function createEditor() {
            StackExchange.prepareEditor({
            heartbeatType: 'answer',
            autoActivateHeartbeat: false,
            convertImagesToLinks: true,
            noModals: true,
            showLowRepImageUploadWarning: true,
            reputationToPostImages: 10,
            bindNavPrevention: true,
            postfix: "",
            imageUploader: {
            brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
            contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
            allowUrls: true
            },
            onDemand: true,
            discardSelector: ".discard-answer"
            ,immediatelyShowMarkdownHelp:true
            });


            }
            });














            draft saved

            draft discarded


















            StackExchange.ready(
            function () {
            StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1391813%2fwhy-does-windows-10-assign-different-port-numbers-to-the-same-usb-port-when-plug%23new-answer', 'question_page');
            }
            );

            Post as a guest















            Required, but never shown

























            1 Answer
            1






            active

            oldest

            votes








            1 Answer
            1






            active

            oldest

            votes









            active

            oldest

            votes






            active

            oldest

            votes









            0















            One reason I thought of was that different controller settings / circuits are used in order to enable 3.0 functionality, and therefore a different port is assigned.




            Yes, that's very common on older motherboards. If I know correctly, the same ports are wired through a multiplexer (mux) to two USB controllers at once – an EHCI controller for 1.x/2.x and XHCI for 3.x – and therefore each port is actually two. Of course they're still only routed to one controller at a time, but can be instantly rerouted to the other after their speed is determined.



            If you switch Windows Device Manager to "View by connection" mode, you'll see that the devices even show up under different controllers in the device tree.






            share|improve this answer




























              0















              One reason I thought of was that different controller settings / circuits are used in order to enable 3.0 functionality, and therefore a different port is assigned.




              Yes, that's very common on older motherboards. If I know correctly, the same ports are wired through a multiplexer (mux) to two USB controllers at once – an EHCI controller for 1.x/2.x and XHCI for 3.x – and therefore each port is actually two. Of course they're still only routed to one controller at a time, but can be instantly rerouted to the other after their speed is determined.



              If you switch Windows Device Manager to "View by connection" mode, you'll see that the devices even show up under different controllers in the device tree.






              share|improve this answer


























                0












                0








                0








                One reason I thought of was that different controller settings / circuits are used in order to enable 3.0 functionality, and therefore a different port is assigned.




                Yes, that's very common on older motherboards. If I know correctly, the same ports are wired through a multiplexer (mux) to two USB controllers at once – an EHCI controller for 1.x/2.x and XHCI for 3.x – and therefore each port is actually two. Of course they're still only routed to one controller at a time, but can be instantly rerouted to the other after their speed is determined.



                If you switch Windows Device Manager to "View by connection" mode, you'll see that the devices even show up under different controllers in the device tree.






                share|improve this answer














                One reason I thought of was that different controller settings / circuits are used in order to enable 3.0 functionality, and therefore a different port is assigned.




                Yes, that's very common on older motherboards. If I know correctly, the same ports are wired through a multiplexer (mux) to two USB controllers at once – an EHCI controller for 1.x/2.x and XHCI for 3.x – and therefore each port is actually two. Of course they're still only routed to one controller at a time, but can be instantly rerouted to the other after their speed is determined.



                If you switch Windows Device Manager to "View by connection" mode, you'll see that the devices even show up under different controllers in the device tree.







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Jan 8 at 10:26









                grawitygrawity

                233k36494549




                233k36494549






























                    draft saved

                    draft discarded




















































                    Thanks for contributing an answer to Super User!


                    • Please be sure to answer the question. Provide details and share your research!

                    But avoid



                    • Asking for help, clarification, or responding to other answers.

                    • Making statements based on opinion; back them up with references or personal experience.


                    To learn more, see our tips on writing great answers.




                    draft saved


                    draft discarded














                    StackExchange.ready(
                    function () {
                    StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fsuperuser.com%2fquestions%2f1391813%2fwhy-does-windows-10-assign-different-port-numbers-to-the-same-usb-port-when-plug%23new-answer', 'question_page');
                    }
                    );

                    Post as a guest















                    Required, but never shown





















































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown

































                    Required, but never shown














                    Required, but never shown












                    Required, but never shown







                    Required, but never shown







                    Popular posts from this blog

                    How to make a Squid Proxy server?

                    Is this a new Fibonacci Identity?

                    19世紀