Just installed Ubuntu 15.10, and my second monitor does not use the correct resolution. It defaults to 1024x768, even though it should support 1920x1080. Previously, on Windows this was not a problem. I had this same problem with this monitor on Arch Linux, and was able to correct it like this:

  • The EDID had a bad checksum
  • Set the IgnoreEDIDChecksum option on the Xorg configuration file
  • In /etc/X11/xorg.conf, under the Device section:

    Option "IgnoreEDIDChecksum" "DFP-4"

I'm not able to find that config option in Ubuntu (and I'm not sure if there is a better way to do it). I've also tried adding a new mode through xrandr, but would get the following error:

xrandr --addmode DVI-D-0 1920x1080_60.00
X Error of failed request:  BadMatch (invalid parameter attributes)
  Major opcode of failed request:  140 (RANDR)
  Minor opcode of failed request:  18 (RRAddOutputMode)
  Serial number of failed request:  41
  Current serial number in output stream:  42

Does anybody know how I can correct the problem, or how I can provide more information? I'm using the proprietary NVIDIA driver (the open source driver would just display a black screen on that monitor).


I was able to fix the issue by generating an xorg.conf file through the NVIDIA settings application, then making the following entry in the Device section:

Option "IgnoreEDIDChecksum" "DFP-4"

Where DFP-4 is the name of the monitor.

| improve this answer | |
  • I'm having the same issue, but my xorg.conf file has three different DEVICE sections. Which one did you add that line to? – neuronet Sep 11 '17 at 13:45
  • @neuronet sorry for the delayed response. I'm not using the same setup anymore, so don't know for sure what the config looks like. If I remember correctly, I only had one DEVICE section. Either that, or I just put this in the first one that I found. – nicksmaddog Sep 15 '17 at 18:28

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