Ubuntu overlapping displays while scaling dual monitor setup
Table of Contents
Today, again I wanted to change my screen's display size, in my Ubuntu 14.04. This time I have a dual monitor setup and I tried all the commands I mentioned in my blog post Ubuntu scaling the display (Zooming).\\
1➜ ~ xrandr
2Screen 0: minimum 8 x 8, current 2560 x 1024, maximum 16384 x 16384
3VGA-0 connected 1280x1024+1280+0 (normal left inverted right x axis y axis) 376mm x 301mm
4 1280x1024 60.0*+ 75.0
5 1152x864 75.0
6 1024x768 75.0 60.0
7 800x600 75.0 60.3
8 640x480 75.0 59.9
9LVDS-0 connected (normal left inverted right x axis y axis)
10 1600x900 60.0 + 40.0
11DP-0 connected primary 1280x1024+0+0 (normal left inverted right x axis y axis) 376mm x 301mm
12 1280x1024 60.0*+ 75.0
13 1152x864 75.0
14 1024x768 75.0 60.0
15 800x600 75.0 60.3
16 640x480 75.0 59.9
17DP-1 disconnected (normal left inverted right x axis y axis)
18HDMI-0 disconnected (normal left inverted right x axis y axis)
19DP-2 disconnected (normal left inverted right x axis y axis)
20DP-3 disconnected (normal left inverted right x axis y axis)
21➜ ~ xrandr --output DP-0 --scale 1.25x1.25
22➜ ~ xrandr --output VGA-0 --scale 1.25x1.25
23➜ ~ xrandr
24Screen 0: minimum 8 x 8, current 2880 x 1280, maximum 16384 x 16384
25VGA-0 connected 1600x1280+1280+0 (normal left inverted right x axis y axis) 376mm x 301mm
26 1280x1024 60.0*+ 75.0
27 1152x864 75.0
28 1024x768 75.0 60.0
29 800x600 75.0 60.3
30 640x480 75.0 59.9
31LVDS-0 connected (normal left inverted right x axis y axis)
32 1600x900 60.0 + 40.0
33DP-0 connected primary 1600x1280+0+0 (normal left inverted right x axis y axis) 376mm x 301mm
34 1280x1024 60.0*+ 75.0
35 1152x864 75.0
36 1024x768 75.0 60.0
37 800x600 75.0 60.3
38 640x480 75.0 59.9
39DP-1 disconnected (normal left inverted right x axis y axis)
40HDMI-0 disconnected (normal left inverted right x axis y axis)
41DP-2 disconnected (normal left inverted right x axis y axis)
42DP-3 disconnected (normal left inverted right x axis y axis)Though it changes the display size, both the screens had overlapping images. After so much analysis, I found one inconsistency in the output of xrandr, before and after scaling. Note the first two lines.\\
1Screen 0: minimum 8 x 8, current 2560 x 1024, maximum 16384 x 16384
2VGA-0 connected 1280x1024+1280+0 (normal left inverted right x axis y axis) 376mm x 301mm
3...
4Screen 0: minimum 8 x 8, current 2880 x 1280, maximum 16384 x 16384
5VGA-0 connected 1600x1280+1280+0 (normal left inverted right x axis y axis) 376mm x 301mmIndividual screen's resolution has scaled to 1600x1280 from 1280x1024, but the total screen size is 2880 x 1280, also the screen's position is 1280x0 instead of 1600x0. So, to get over the overlapping problem, I used the following command, after reboot, and it worked\\
1➜ ~ xrandr --output DP-0 --scale 1.25x1.25 --pos 0x0 --output VGA-0 --scale 1.25x1.25 --pos 1600x0
2➜ ~ xrandr
3Screen 0: minimum 8 x 8, current 3200 x 1280, maximum 16384 x 16384
4VGA-0 connected 1600x1280+1600+0 (normal left inverted right x axis y axis) 376mm x 301mm
5 1280x1024 60.0*+ 75.0
6 1152x864 75.0
7 1024x768 75.0 60.0
8 800x600 75.0 60.3
9 640x480 75.0 59.9
10LVDS-0 connected (normal left inverted right x axis y axis)
11 1600x900 60.0 + 40.0
12DP-0 connected primary 1600x1280+0+0 (normal left inverted right x axis y axis) 376mm x 301mm
13 1280x1024 60.0*+ 75.0
14 1152x864 75.0
15 1024x768 75.0 60.0
16 800x600 75.0 60.3
17 640x480 75.0 59.9
18DP-1 disconnected (normal left inverted right x axis y axis)
19HDMI-0 disconnected (normal left inverted right x axis y axis)
20DP-2 disconnected (normal left inverted right x axis y axis)
21DP-3 disconnected (normal left inverted right x axis y axis)Now, you see that both the actual size of the screen and the starting position of the second screen is set properly.\\