DPI inconsistency

[Matthieu Herrb]

On Wed, Dec 28, 2022 at 10:51:29AM -0800, Yuri wrote:
> My NVidia card has the resolution 3840x2160.
> 
> xorg.conf has this section, following the recommendation from
> https://linuxreviews.org/HOWTO_set_DPI_in_Xorg:
> 
> Section "Monitor"
>         Identifier   "Monitor0"
>         VendorName   "Monitor Vendor"
>         ModelName    "Monitor Model"
>         DisplaySize  630 340    # In millimeters - setting for DPI
> EndSection
> 
> 
> Xorg.0.log has:
> 
> > [ 37714.549] (--) NVIDIA(0): DPI set to (159, 156); computed from
> "UseEdidDpi" X config
> 
> 
> Based on the DPI computation for resolution 3840x2160 and size 630mm x 340mm
> - DPI should be 155x161.
> 
> This is close to what Xorg.0.log has, but is not equal to it.
> 
> 
> But xdpyinfo shows 96x96:
> 
> > xdpyinfo | grep -B 2 resolution
> > screen #0:
> >   dimensions:    3840x2160 pixels (1016x572 millimeters)
> >   resolution:    96x96 dots per inch
> 
> 
> Why doesn't the xorg.conf setting of DisplaySize translate into the actual
> DPI value in xorg that xdpyinfo shows?
> 
> 
> Thank you,

Hi,

are you using Xfce ? if so it's an old issue :
https://bugzilla.xfce.org/show_bug.cgi?id=10633
moved to:
https://gitlab.xfce.org/xfce/xfce4-settings/-/issues/34

and also :
https://gitlab.xfce.org/xfce/xfce4-settings/-/issues/190
-- 
Matthieu Herrb