5

I am having problems setting up a right resolution after changing HDMI->DisplayPort adapter (converter).

My setup:

As this monitor has a HDMI cable and the laptop has only Display port, I am using a DisplayPort to HDMI adapter. Everything worked until recently (I was able to set 2560x1440 resolution without any problem). Cable is probably old and it started to disconnect and connect quite often (turning the screen off for few seconds). I decided to get a new adapter so I got ICY BOX (up to 4K resolution, they say).

It is already the second one I am trying but I am not able to select higher resolution with it than 1920x1080:

enter image description here

But I am able to do that with an old cable which is constantly reconnecting:

enter image description here

I have no idea what brand is the old adapter but it looks pretty normal:

enter image description here

Does anyone have an idea what might be the problem?

EDIT

With old adapter (has 2560x1440 but old and needs to be replaced):

matt:~ $ xrandr --listmonitors
Monitors: 1
 0: +*DP-3 2560/597x1440/336+0+0  DP-3
matt:~ $ xrandr -q
Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 8192 x 8192
LVDS-1 connected (normal left inverted right x axis y axis)
   1600x900      60.04 +  59.99    59.94    59.95    59.82    40.02  
   1440x900      59.89  
   1400x900      59.96    59.88  
   1440x810      60.00    59.97  
   1368x768      59.88    59.85  
   1360x768      59.80    59.96  
   1280x800      59.99    59.97    59.81    59.91  
   1152x864      60.00  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   800x512       60.17  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   720x450       59.89  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   680x384       59.80    59.96  
   640x400       59.88    59.98  
   576x432       60.06  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
VGA-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
HDMI-3 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
   2560x1440     59.95*+
   1920x1080     60.00    50.00    59.94  
   1680x1050     59.88  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1440x900      59.90  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    72.81    66.67    60.00    59.94  
   720x400       70.08  
  2560x1440_60.00 (0x18b) 312.250MHz -HSync +VSync
        h: width  2560 start 2752 end 3024 total 3488 skew    0 clock  89.52KHz
        v: height 1440 start 1443 end 1448 total 1493           clock  59.96Hz

With new adapter (the one without 2560x1440 resolution):

matt:~ $ xrandr --listmonitors
Monitors: 1
 0: +*HDMI-3 1920/597x1080/336+0+0  HDMI-3
matt:~ $ xrandr -q
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
LVDS-1 connected (normal left inverted right x axis y axis)
   1600x900      60.04 +  59.99    59.94    59.95    59.82    40.02  
   1440x900      59.89  
   1400x900      59.96    59.88  
   1440x810      60.00    59.97  
   1368x768      59.88    59.85  
   1360x768      59.80    59.96  
   1280x800      59.99    59.97    59.81    59.91  
   1152x864      60.00  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   800x512       60.17  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   720x450       59.89  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   680x384       59.80    59.96  
   640x400       59.88    59.98  
   576x432       60.06  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
VGA-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
HDMI-3 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
   1920x1080     60.00*   50.00    59.94  
   1680x1050     59.88  
   1600x900      60.00  
   1280x1024     75.02    60.02  
   1440x900      59.90  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    72.81    66.67    60.00    59.94  
   720x400       70.08  
DP-2 disconnected (normal left inverted right x axis y axis)
DP-3 disconnected (normal left inverted right x axis y axis)
  2560x1440_60.00 (0x18b) 312.250MHz -HSync +VSync
        h: width  2560 start 2752 end 3024 total 3488 skew    0 clock  89.52KHz
        v: height 1440 start 1443 end 1448 total 1493           clock  59.96Hz
7
  • Can you have a look to connector PINs? Are they the same among old and new adapter? In the past I had a similar issue and I discovered the broken cable (in my case) had less pins on one connector than the same connector for the other cable...
    – mattia.b89
    Feb 9, 2020 at 13:47
  • What do you mean by connector PIN?
    – matt525252
    Feb 10, 2020 at 8:15
  • The physical part of the connector that touches the other connector. See the image images.app.goo.gl/XEzZu1ZKda4KQtyR7
    – mattia.b89
    Feb 10, 2020 at 18:09
  • Unless the hardware is dodgy (definitely a possibility) I think you are looking for askubuntu.com/questions/377937/how-to-set-a-custom-resolution
    – Elder Geek
    Feb 13, 2020 at 17:46
  • I tried but did not really work.
    – matt525252
    Feb 14, 2020 at 21:36

2 Answers 2

1

I had almost the exact same problem. The issue involve HDMI and DisplayPort cables. The physical resolution of my monitor is 1920x1080. Recently my Apple Thunderbolt 2560x1440 died on me. So, the only monitor I had at hand was an LG with 1920x1080 with both HDMI and DisplayPort ports. I wanted 2506x1440 because I got used to it.

I connected the monitor with an HDMI cable to my Ubuntu 18.04 machine, and all that Ubuntu could see was a maximum of 1920x1080. I tried all the settings with xrandr and still the monitor didn't want to switch. So, instead of HDMI, I got the DisplayPort cable and connected it to the monitor. Ubuntu still sees the maximum physical resolution 1920x1080 but xrandr can set at much higher resolutions. For example, this setting put the monitor at 2560x1440:

xrandr --output DP-2 --auto --scale-from 2560x1440

This is the easiest and faster way to resize logically the resolution of the monitor. More elaborated scripts require to play a little bit more with xrandr,. Like this one:

xrandr --newmode "2464x1383_60.00"  287.50  2464 2640 2904 3344  1383 1386 1396 1434 -hsync +vsync
xrandr --addmode DP-2 2464x1383_60.00
xrandr --output  DP-2 --mode 2464x1383_60.00

You get the long line of settings for --newmode from running cvt. In my case cvt 2458 1383 60.

Although all of this works well -almost well I should say- the only minor nuisance is the quality of the pixelation. That is understandable because my monitor is physically limited at 1920x1080. But that shouldn't be an issue with monitors with real physical resolution of 2560x1440 as your Samsung 27" CH711 is.

Again, the easiest way to see this would work for you is first starting with auto scale, and then move to a more elaborated settings.

3
  • Did not work :/
    – matt525252
    Feb 14, 2020 at 21:19
  • what are your xrandr settings when you use the DisplayPort cable?
    – f0nzie
    Feb 15, 2020 at 22:17
  • I updated my questions so you can see it for both (old and new) adapters.
    – matt525252
    Feb 16, 2020 at 8:43
0

Many approached of adding the custom resolution utilises the cvt to generate the modeline values for the monitor.

For me this approch didn't work.

So, I tried using the modeline values that my windows10 was using after capturing the edid. And it worked.

You can also try using the modeline that windows uses. For capturing the edid use "monitor asset manager" software.

Hope this helps.

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