9 Replies Latest reply on Jan 22, 2016 10:25 AM by EstebanC_Intel

    Baytrail dual display capabilities

    CA01

      Hi,

       

      I have a system with Baytrail processors (E3480, E3823, E3822, and others) that disables the LVDS when display port is connected during boot up. I have been trying to look on the internet if that is a dual display combination that should work or not. Does anyone know if this should work and where I can find this information for future reference?

       

      Regards

        • 1. Re: Baytrail dual display capabilities
          EstebanC_Intel

          Hello, CA01:

           

          Thank you for contacting the Intel® Communities.

           

          I would like to know if you are able to select a default output device for the display at BIOS level.

           

          If this is positive, what are the options to select there?

           

          I look forward to hearing from you.

           

          Regards,

          Esteban C

          • 2. Re: Baytrail dual display capabilities
            CA01

            Hi Esteban,


            The BIOS just allows me to select between internal graphics or PCIE. But my question is more related to the VBIOS capabilities, i.e. whether the VBIOS, if configured properly, would be able to show the image on the LVDS and DP at the same time.

             

            I know the VBIOS can be modified to boot from the LVDS when both DP and LVDS are connected, but I need to know if there is a processor limitation to accomplish dual display when using these two interfaces. So far I have measured the LVDS signals and the whole LVDS port is disabled when connecting something to the DP.

             

            Regards

            • 3. Re: Baytrail dual display capabilities
              EstebanC_Intel

              Hello:

               

              Is this only while you are at the BIOS?

               

              Do you have the option to manually select a "primary" display in BIOS?

               

              At BIOS, the dual display is not available since all the drivers are loaded until the system boots to the OS.

               

              Please let us know if this the scenario in your system.

               

              Regards,

              Esteban C

              • 4. Re: Baytrail dual display capabilities
                CA01

                Hi Esteban,

                 

                Yes, this is only at boot-up, inside the operating system works fine. Also, in the BIOS I can only select between internal graphics or PCIE, as mentioned before

                 

                On the other hand, I understand all drivers are loaded until the operating system boots, but that is why I would like information about the VBIOS capabilities. I know the VBIOS is capable of dual display but is limited to some configurations, i.e. CRT+DP work but CRT+HDMI will not.

                 

                Could you please let me know what dual display configurations can be accomplished by the VBIOS? Or at least let me know if LVDS+DP would work?

                 

                We actually have the possibility to change the VBIOS and create a new BIOS version, but before I get in touch with the BIOS team, I would like to find out first what options we have.

                 

                Regards,

                Carlos

                • 5. Re: Baytrail dual display capabilities
                  EstebanC_Intel

                  Hello, CA01:

                   

                  I would like you to check this article related to enabling dual display in DOS or VBIOS.

                  http://www.intel.my/content/dam/www/public/us/en/documents/application-notes/dual-displays-during-startup-appl-note.pdf

                   

                  I look forward to your feedback on this.

                   

                  Regards,

                  Esteban C

                  • 6. Re: Baytrail dual display capabilities
                    CA01

                    Hi Esteban,

                     

                    I understand the difference between the VESA and VGA modes, but the document doesn’t answer my question directly. I know Intel sometimes has documentation with tables showing what interfaces should work with dual display in VBIOS, which is based on what data can be sent to two displays on the same pipe.

                     

                    Since the VBIOS comes from the Graphics team, normally they use VGA modes and I am not sure about EMGD. I also know that EMGD and normal VBIOS are different.

                     

                    But still, I don’t think my question is completely understood. I don’t need help to enable dual display in the VBIOS, what I need to know is if there is a limitation from the VBIOS to enable dual display between LVDS and DP, as they would be using the same pipe.

                     

                    Regards,

                    Carlos

                    • 7. Re: Baytrail dual display capabilities
                      EstebanC_Intel

                      Hello, CA01:

                       

                      I found the information below in the link shared previously.

                       

                      Page 4 http://www.intel.my/content/dam/www/public/us/en/documents/application-notes/dual-displays-during-startup-appl-note.pdf?…

                       

                      : " Pipe Limitations

                      Many of the built-in display ports on Intel chipsets available now (such as LVDS, eDP,

                      etc.) have a restriction, by design, that does not allow them to share their pipe with

                      another port. Thus, by definition, you cannot Twin them, and must Clone them which

                      tends to be what is needed anyway."

                       

                      I hope this clarifies your inquiry.

                       

                      If more information or support is required, feel free to contact us back.

                       

                      Regards,

                      Esteban C

                      • 8. Re: Baytrail dual display capabilities
                        CA01

                        Hi Esteban,

                         

                        I did read the document and I understand I cannot twin the displays. However, it says I can clone the displays, but I seriously doubt every dual display combination will work as long as I use clone mode, since the data going through the pipe changes according to the EDID used.

                         

                        Since we have been going around in circles with this question, I would just ask a yes/no question:

                         

                        - Is the VBIOS capable of cloning LVDS+DP on Baytrail?

                         

                        I am not trying to be rude but I was expecting a more direct answer.

                         

                        Regards,

                        Carlos

                        • 9. Re: Baytrail dual display capabilities
                          EstebanC_Intel

                          Hello, CA01:

                           

                          In order to get a dual display at BIOS level, you would have to modify the BIOS (this will be done by OEM) to enable the clone feature in it.

                           

                          My recommendation would be to check with the manufacturer of your device to check if this can be done.

                           

                          With a regular system, dual display at BIOS is not enable.

                           

                          Regards,

                          Esteban C