I’ve been wanting to make this work for a long time, but the two times I tried to configure it I gave up because I just didn’t know what else to do. This time I sat down and didn’t get up until it worked. I worked on the xorg.conf several times before, so I know my way around it. It was still quite a puzzle for me to get working. If you want to know how to configure a display without EDID on Linux, click here. First I tried using the X way. Multiple Monitors with a Screen each, using one Device, put together in a ServerLayout.

I already got a lot of the necessary information from a post by Pat Regan that you should definitely read before starting to play around with your settings! At first I tried to configure my new QX2710 with my old monitor connected, but I figured I might aswell just do it remotely. So I connected to my computer from my laptop via SSH and played around with the xorg.conf. After applying the changes I’d restart lightdm (sudo service lightdm restart) until it worked. In the meantime my monitor showed me this: I ended up using HorizSync 89.52 - 160.0, VertRefresh 59.