A few days ago I was lucky enough to obtain a free monitor and I decided to buy a VGA splitter to use it with my other screen. The splitter is an Aten VS92A, if it can be useful.
The device works perfectly, the signal goes to both screens, but for some reason the computer can't see it's connected to two different screens. Instead I see the same view on both monitors.
To clarify a bit the situation: I'm using a laptop, so in fact I now have three different screens (but the idea is to shut down the laptop screen as soon as everything works because it renders colors really badly) and the laptop screen is successfully distinguished from the other two. This also means that installing a new graphic card is sadly not an option. Other cables (e.g. HDMI) are also not an option.
I found other cases similar to mine, but I can't find a solution that works for me. As I understand, it seems that the computer doesn't identify the EDID of the second screen and to further confirm this hypothesis I can say that, if I switch the cables connected to the splitter, the resolution adapts to the best settings for the screen connected on port 1.
I also saw a lot of people saying: "with linux I see twice the same image and with windows a split screen." This means that the splitter sends all the useful information to the computer, but the computer can't see it or it doesn't even look for it. Sadly (not really) I don't have windows installed on my computer, so I can't verify this step, but the splitter manual said indeed that it is possible to obtain a split screen, otherwise I wouldn't have bought it.
Now, for the useful information about my computer:
uname -a Linux #### 3.19.0-65-generic #73-Ubuntu SMP Tue Jun 28 17:02:53 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
Desktop environment: MATE
cat /etc/X11/default-diplay-manager usr/sbin/lightdm xrandr -q Screen 0: minimum 8 x 8, current 3286 x 1080, maximum 32767 x 32767 LVDS1 connected 1366x768+0+312 (normal left inverted right x axis y axis) 309mm x 174mm 1366x768 60.0*+ 1360x768 59.8 60.0 1024x768 60.0 800x600 60.3 56.2 640x480 59.9 DP1 disconnected (normal left inverted right x axis y axis) HDMI1 disconnected (normal left inverted right x axis y axis) VGA1 connected 1920x1080+1366+0 (normal left inverted right x axis y axis) 473mm x 300mm 1920x1080 60.0*+ 1680x1050 60.0 1280x1024 75.0 60.0 1280x800 59.8 1152x864 75.0 1280x720 60.0 1024x768 75.1 70.1 60.0 832x624 74.6 800x600 72.2 75.0 60.3 56.2 848x480 60.0 640x480 75.0 72.8 66.7 60.0 59.9 720x400 70.1 VIRTUAL1 disconnected (normal left inverted right x axis y axis)
And switching monitors on the splitter the same command shows (only the different part):
VGA1 connected 1440x900+1366+0 (normal left inverted right x axis y axis) 408mm x 255mm 1440x900 59.9*+ 75.0 1680x1050 60.0 1280x1024 75.0 60.0 1280x800 59.8 1152x864 75.0 1280x720 60.0 1024x768 75.1 70.1 60.0 832x624 74.6 800x600 72.2 75.0 60.3 56.2 848x480 60.0 640x480 75.0 72.8 66.7 60.0 59.9 720x400 70.1
Content of /var/log/Xorg.0.log: http://pastebin.com/TgfnQzJU
I can't find xorg.conf, but there are two files that have both the same content, formatted as a few examples of xorg.conf I found elsewhere, they are called xorg.conf.07292015 and xorg.conf.07302015 and their content can be found here: http://pastebin.com/gUBBGRti
The available drivers and the one in use can be found in this screenshot:
nvidia-settings -q all
returns an empty line.
Intuitively it seems to me that xrandr should see a VGA2 together with VGA1, but with different settings. Any suggestion?