Yes you should create the /etc/X11/xorg.conf.d yourself.
system-setup-keyboard package has an example file to setup KB.
You can ....
sudo mkdir /etc/X11/xorg.conf.d
sudo X -configure :1
sudo cp /root/xorg.conf.new /etc/X11/xorg.conf.d/00-myfile.conf
or otherwise run commands as root.
This creates a baseline file in /etc/X11/xorg.conf.d/00-myfile.conf which you will need to edit.
Next do this on YOUR system to calculate a mode and timing for that resolution (assumes 60hz).
Code:
[root@crucibulum X11]# cvt -v 1600 900 60
# 1600x900 59.95 Hz (CVT 1.44M9) hsync: 55.99 kHz; pclk: 118.25 MHz
Modeline "1600x900_60.00" 118.25 1600 1696 1856 2112 900 903 908 934 -hsync +vsync
You need to insert that exact Modeline test into the Monitor0 section of your 00-myfile.conf
It's been years since I played w/ this but you may need to add one more line like
Mode "1600x900_60.00"
to actually select that mode.
Maybe
Code:
...
Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
Modeline "1600x900_60.00" 118.25 1600 1696 1856 2112 900 903 908 934 -hsync +vsync
Mode "1600x900_60.00"
EndSection
...
Hopefully someone who's been through this recently can add a few details.
---------- Post added at 01:31 AM ---------- Previous post was at 01:25 AM ----------
Sorry for the complexity - this used to be a lot simpler before EDID and autoconfiguration. But now you are out on a thin branch with a display that's not ID'ing a good default resolution.