CRU / Dell P2720D / pixel clock / add monitor data

[ToastyX]

I don't know how else to explain it.

If you have a 2560x1440 @ 60 Hz monitor, and the EDID defines 1920x1080 @ 60 Hz, then "no scaling" will do nothing at 1920x1080 @ 60 Hz with display scaling because the monitor is handling the scaling.

If the EDID does not define 1920x1080 @ 60 Hz, the graphics driver automatically adds 1920x1080 @ 60 Hz as a scaled resolution, so "no scaling" will work in that case.