I have read through HOWTO enable 10-bit color on Linux and know how to create a basic multi-monitor config file. The issue is that I only see it possible to enable 10-bit for the entire screen, not a single monitor.
I have tried just setting the option "Depth" on each monitor, but it does not change it: Unionwell
Section "Monitor"
Identifier "DisplayPort-0"
Modeline "2560x1440_144.00" 807.69 2560 2784 3072 3584 1440 1441 1444 1565 -HSync +Vsync
Option "Depth" "24"
EndSection
Section "Monitor"
Identifier "DisplayPort-1"
Modeline "3840x2160_60.00" 712.34 3840 4152 4576 5312 2160 2161 2164 2235 -HSync +Vsync
Option "Depth" "30"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Radeon"
Monitor "DisplayPort-0"
EndSection
I have checked and that monitor is 10-bit capable as reported by the Xorg.0.log
[ 10941.739] (II) AMDGPU(0): EDID for output DisplayPort-1
[ 10941.739] (II) AMDGPU(0): Manufacturer: GSM Model: 5b09 Serial#: 15673
[ 10941.739] (II) AMDGPU(0): Year: 2017 Week: 9
[ 10941.739] (II) AMDGPU(0): EDID Version: 1.4
[ 10941.739] (II) AMDGPU(0): Digital Display Input
[ 10941.739] (II) AMDGPU(0): 10 bits per channel
However I only see one instance of:
[ 10941.597] (==) AMDGPU(0): Depth 24, (--) framebuffer bpp 32
[ 10941.597] (II) AMDGPU(0): Pixel depth = 24 bits stored in 4 bytes (32 bpp pixmaps)
Which I'd imagine I should have two, one of Depth 24, and one of Depth 30.
I am using the amdgpu-pro graphics drivers on Ubuntu 20.04 if that makes a difference.