10 Replies Latest reply on Aug 2, 2018 5:22 AM by Robicek77

    Cannot get full RGB quantization range over native DisplayPort on HD 630 integrated graphics

    nstommel

      I recently purchased an HP Elitedesk 800 G3 Mini Desktop which comes with integrated Intel HD 630 graphics on a premium Kabylake 7700T chipset. Two of the three outputs on the back are full-sized DisplayPort. My problem here is that on Windows, I simply cannot get full RGB color quantization 0:255 on my computer monitor at all. Instead, I am getting clamped RGB 16:235 from native DisplayPort outputs. It is most certainly not a problem with the underlying hardware or the BIOS, as this issue is nonexistent on Linux if full range is selected, and it is very clear from the boot splash screen and Linux usage that the ports can output full, unclamped RGB. It is also not a problem exclusive to OEM Intel drivers, as HP's supplied drivers for Windows as well as the newest versions of the Kabylake HD 630 driver I have obtained from Windows Update or directly from Intel's site results in the same exact problem: limited RGB quantization over native DisplayPort out. There are no adapters or anything weird going on here, just direct DP to DP.

       

      The difference between full RGB and limited RGB is nothing short of absolutely jarring. On Linux, clamping and unclamping the DP RGB range is easily accomplished using "xrandr --output DP-1 --set "Broadcast RGB" "Full"" (unclamped/full) or "xrandr --output DP-1 --set "Broadcast RGB" "Limited 16:235"" (clamped/limited). On Windows, however, I am stuck with the Intel driver delivering only 16:235 limited colors over native DisplayPort connections. The issue is especially apparent when, for example, opening the legacy command prompt in fullscreen and observing how different from black the background really is. This color issue applies to the entire Windows desktop environment, and changing the options in the Intel HD Graphics Control Panel -> Video -> Color Enhancement -> Input Range has no effect whatsoever on the picture. Selecting Automatic, Limited, or Full all give the exact same disappointing and frustrating result: Limited 16:235 RGB. I've tried everything from setting color profiles to registry hacks, but nothing works.

        • 1. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
          Intel Corporation
          This message was posted on behalf of Intel Corporation

          Hello nstommel,

          I understand that you are having problems with the full RGB when using it over Display Port.

          Regarding this, I would like to first gather some information about your system, starting with an Intel ® System Support Utility report. You can get this report by using our tool which you can download in the link below:

          https://downloadcenter.intel.com/download/25293/Intel-System-Support-Utility-for-Windows-

          Also, to better assist you with your request, I will need to check some information about your computer. Please follow these steps: 

          1. In the keyboard, press WinLogo key + R. 
          2. In the Run box please type dxdiag and hit Enter.
          3. Click on Save All Information (save it in your desktop). 
          4. Attach the report to this thread. 

          If possible, please also attach a graphics report, you can refer to the link below on how to create a report:

          https://www.intel.com/content/www/us/en/support/articles/000005848/graphics-drivers.

          Finally, please try to use a different driver, an older one. You can try with the driver that I will provide you below, it is to check and see if the problem is with the driver or something else:

          https://downloadcenter.intel.com/download/27058/Intel-Graphics-Driver-for-Windows-15-46-?product=98909

          Download the ".zip" file and follow these steps in order to install it: 

          1 - Unzip the file to a designated location or folder. 
          2 - Right-click Windows Start icon and open Device Manager.
          3 - Click Yes when prompted for permission from User Account Control. 
          4 - Expand the Display adapters section. 
          5 - Right-click the Intel® graphics entry and select Update Driver Software. 
          6 - Click "Browse my computer for driver software".
          7 - Click "Let me pick from a list of device drivers on my computer".
          8 - Click "Have Disk". 
          9 - Click "Browse". 
          10 - Access the designated location or folder, and access a folder called "Graphics". 
          11 - Select the file called "igdlh64" or "igdlh"(Setup information file). 
          12 - Click Open, then click OK, and finally click Next. Drivers are now being installed. 
          13 - Reboot your computer

          I hope this helps.


          Regards,
          David V

          1 of 1 people found this helpful
          • 2. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
            nstommel

            Thank you very much for the considerate reply, that means a lot to me. My sincerest apologies for not replying sooner, I have been somewhat busier than anticipated. I will try all the things you suggested and use the utility to give you a comprehensive look at the hardware tomorrow. To give you a better 'blank' testing bed for this odd driver issue, I will use a fresh Windows 10 Pro installation on my Elitedesk 800 G3 DM. I have reset the machine before, but I have never received proper full 0:255 RGB out over Displayport on Windows using the HD 630 iGPU, nor can I force it through the driver configuration panel.

            • 3. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
              Intel Corporation
              This message was posted on behalf of Intel Corporation

              Hello nstommel,

              Thank you for your response.

              It is my pleasure to assist you with this so we can find the cause of this problem that is currently affecting your system. Please take your time and provide me with the information whenever is best for you. As soon as I have that information, I will begin to analyze it and check what the problem can be. 

              I hope to hear from you.


              Regards,
              David V

              • 4. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
                nstommel

                Here is the full exported text of the Intel System Support Utility scan for Windows on my system ("ssu.txt"). Full dxdiag output is also attached ("DxDiag.txt"). Finally, I also have the exported text from the graphics Report for Intel Graphics Drivers attached ("Intel(R) HD Graphics 630 Thursday, July 26, 2018.txt").

                 

                I regret to report that installing the older driver using the steps detailed had no effect on the output RGB range, it still remains at limited 16:235 over DisplayPort. 

                • 5. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
                  Intel Corporation
                  This message was posted on behalf of Intel Corporation

                  Hello nstommel,

                  Thank you for your response.

                  I was reviewing the information and everything seems to be in order. I want to try a clean install of the graphics driver to test. In order to do so, please follow the steps below:

                  1 - Download the .zip driver from https://downloadcenter.intel.com/download/27892/Intel-Graphics-Driver-for-Windows-10?product=98909
                  2 - Disconnect the computer from the internet. 
                  3 - Go to device manager and check under display adapters.
                  4 - Right-click on the Intel ® Integrated Graphics, select the option uninstall and keep going until you only have Microsoft's basic display adapter.
                  5 - Unzip the file you downloaded previously.
                  6 - Right-click on the Microsoft's basic display adapter and select "Update driver".
                  7 - Select the option "Browse my computer for driver software.
                  8 - Select the option "Let me pick from a list of device drivers on my computer". 
                  9 - Select the option "Have disk".
                  10 - Select the option "Browse".
                  11 - Access the designated location or folder where you unzipped the driver downloaded and access a folder called "Graphics". 
                  12 - Select the setup information file (Typically named either "idglh64" or "igdlh").
                  13 - Click on open and then click OK, finally click Next and the drivers will begin to install. 
                  14 - Reboot your computer when the installation is completed.

                  Once the reboot is completed you can connect back to the internet. Please check to see if the RGB is still the same.

                  I hope this helps.


                  Regards,
                  David V

                  • 6. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
                    nstommel

                    Unfortunately, this had no effect. I can only get full RGB quantization in the actual interface over HDMI. The "Quantization Range" option is missing from the Intel HD Graphics Control Panel settings when connected via DisplayPort, but is present when connected through HDMI. Full Range quantization should be enabled by default over DisplayPort because no televisions even have DisplayPort inputs. Full Range RGB should just work without having to set anything, as basically all computer monitors with DisplayPort inputs display and take a full-range RGB 0:255 signal, not limited default HDMI 16:235.

                    • 7. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
                      Intel Corporation
                      This message was posted on behalf of Intel Corporation

                      Hello nstommel,

                      Thank you for your response.

                      Since we have not been able to find a solution for this still, I will proceed to do some research and testing myself here. Please allow me some time while I finish the testings, I will be getting back to you as soon as possible. 


                      Regards,
                      David V

                      • 8. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
                        Intel Corporation
                        This message was posted on behalf of Intel Corporation

                        Hello nstommel,

                        Thank you for working with me to solve the problem.

                        I would like you to try the following settings and provide me with some information: 

                        1. Open Intel® Graphics Control Panel
                        2. Click Video.
                        3. Click Color Enhancement.
                        4. Under Input Range, click Use Driver Settings.
                        5. Select either Limited Range or Full Range.
                        6. Click Apply
                        After doing that, please take a video showing how it looks with the Display Port connection,and then, with the same settings applied, take a video with the HDMI* connection. This will help us a lot in finding a possible solution for the encountered issue.


                        Regards,
                        David V
                        1 of 1 people found this helpful
                        • 9. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
                          nstommel

                          Okay, I sincerely apologize for the confusion, it happens to actually be a somewhat odd quirk of the Windows UI and color profile settings of the monitor itself. Selecting 'low' black levels in my Samsung monitor's settings over HDMI actually ends up chopping off a huge part of the lower and upper contrast range. When changing the black levels setting to 'normal' over HDMI with color quantization set to 'full' in the Intel Graphics Control Panel, I correctly get exactly the same picture over DisplayPort without any tweaks. There is also a weird quirk with the Windows UI independent of Intel driver settings where even using just Microsoft's limited display driver, the command prompt and select few elements are off-black regardless of the display input used. Running the PuTTY SSH client and dragging the Windows command prompt window next to it shows this strange quirk in the below picture (the difference in black depth is actually fairly dramatic). Aside from that alarming idiosyncrasy in certain parts of the Windows UI, full range color is actually correctly shown over DisplayPort by default. I discovered that the 'low' black level setting on my monitor messed with the contrast settings by overemphasizing the low and high end of the contrast/color range, so much so that things appeared 'washed out' in comparison. The 'low' black setting was available on my monitor (and many other monitors as well) over HDMI, which is what led me to reason this was a DisplayPort issue). Once I set HDMI black levels to 'normal' on my monitor and did some tweaking, I realized that I was in fact getting full-range RGB over DisplayPort using the HD 630 iGPU as intended. Now colors match appropriately using HDMI or DisplayPort. I found the classic "Lagom" LCD testing images for contrast (http://www.lagom.nl/lcd-test/contrast.php) and black level (http://www.lagom.nl/lcd-test/black.php) quite helpful in figuring this out. Anyways, thank you for bearing with me. There is, in fact, no issue here and the Intel HD 630 iGPU is outputting full-range RGB correctly over Displayport.

                           

                          Screenshot (5).png

                          1 of 1 people found this helpful
                          • 10. Re: Cannot get full RGB quantization range 0:255 over native DisplayPort on HD 630 iGPU
                            Robicek77

                            Try older drivers, 15.45.21.4821 and older. New HDR drivers on DP are all very bugy and color limited (6-bit, and still uncorected).