6 Replies Latest reply on Nov 19, 2016 1:24 AM by maxc

    rx480: cannot get 3840x2160 60hz on Displayport

    maxc

      Hello,

      please help with an issue I cannot resolve.

      My ASUS RX480-8G is connected to 2 LG 27UD88 monitors:

      The main monitor is connected with Displayport and the secondary with HDMI.

      I can get 3840X2160 60Hz 4/4/4 on the secondary monitor but I can only get 3840x2160 30Hz on the primary.

      The primary monitor is reported to be 60Hz capable

      however the Adapter modes don't have the 3840x2160 60Hz option:

      The secondary monitor, connected through HDMI,  runs at 3840x2160 60Hz 4/4/4

      (By the way, the Pixel Format setting is available only on the monitor connected through HDMI, don't know if this is expected)

       

      I also tried to reduce the color depth to 8 bits but nothing changes, and if I connect the secondary monitor with DisplayPort the 60Hz mode disappears and it behaves exactly like the primary.

       

      My configuration:

           OS: W10 Anniversary edition

           AMD Graphic driver: 21.19.151.3 (04-Oct-16)

           Primary Monitor: Displayport, LG Driver 1.0.0.0 (21-Aug-15)

           Secondary Monitor: HDMI (Ultre Deep Color enabled), LG Driver 1.0.0.0 (21-Aug-15)

           Cables: received with the monitors

       

      Thank you for your help,

      Max

        • Re: rx480: cannot get 3840x2160 60hz on Displayport
          catchabreak

          in Radeon additional settings. Now I use a TV as a monitor and the setting is called HDTV support. What it does is allow me to enable screen resolutions that EDID driver is not identifying correctly, Don't Know what its called if you use monitors or if it is available for them, but it did enable me to add some resolutions to my graphics card.

            • Re: rx480: cannot get 3840x2160 60hz on Displayport
              maxc

              the HDTV Support is also available for monitors however it is limited to 720p and 1080i/p resolutions.

              I enabled custom resolutions and I can go up to 3840x2160 60Hz but then I need to enter the manual timing values and I don't know what to enter there:

              Any help?

              Thank you

              Maz

                • Re: rx480: cannot get 3840x2160 60hz on Displayport
                  catchabreak

                  found this little titbit of info not sure if this is relevant

                  "Hi, I know it has been two months but I just got the same monitor and was having the same issue. The solution is just to turn on the Displayport 1.2 in the monitors config since it comes in 1.1 mode when you buy it"

                  LG 27UD88-W Support: Manuals, Warranty & More | LG U.S.A

                  there's a windows 10 driver and some other useful software on their support page for your monitor

                   

                  has                                                                                                                        in the driver

                                      [ULTRA HD_DP.AddReg]

                                      HKR,"MODES\3840,2160",Mode1,,"30.0-135.0,56.0-61.0,+,+"

                                      HKR,,PreferredMode,,"3840,2160,60"

                                      HKR,,ICMprofile,0,"ULTRA HD.ICM"

                  1 of 1 people found this helpful
                    • Re: rx480: cannot get 3840x2160 60hz on Displayport
                      maxc

                      Thank you again.

                      The LG site you refer to is the site where I downloaded my driver and the entry you refer to is in the driver.

                      I did some more tests and connected one monitor to the Intel on-board graphic card of my system and there I could get DP 3840x2160 @ 60Hz. That basically ruled out any issue with the monitor.

                      I did many tests using different DP outputs on my card and at the I suspect I messed up the driver. Currently the Digital Flat-Panel properties of the Radeon Additional settings shows monitor 1 and 2 swapped compared to the Win10 Display setting window:

                      And it gives me some issues, e.g. the system crashes when I switch DVBviewer (a tv viewer SW) to full screen.

                      I don't know how to fix it, I tried to uninstall and reinstall the whole AMD suite with no success.

                      I may end up with a full system reinstall.

                      Thanks,

                      Max

                • Re: rx480: cannot get 3840x2160 60hz on Displayport
                  toxiccharged

                  Hey Max,

                  Maybe I'm a little bit too late but I recently have had the same problem with my relatively new LG 27UD58. After thinking of all possible solutions, I fixed the problem with just turning the monitor off and then turning it on again. My gpu then detected that 4K@60Hz was possible and even automatically switched to 60Hz.

                  I hope this will help because I know that 30Hz on a monitor is really uncomfortable