I have a setup that uses two older monitors with low resolutions.
Monitor A: 1280x1024
Monitor B: 1280x720
The gpu is similarly old: ATI Radeon HD 4850.
I want to limit Monitor A’s resolution to 1280x720 and display the picture unscaled and centered with black bars on top and bottom in order to have both screens mirrored.
Creating a custom resolution and applying it to Monitor A works without problem. Unfortunately the command
xrandr --set “scaling mode” “Center”
has no effect. I only get a stretched picture which looks ugly. When used with an nvidia GPU the intended effect is achieved but there are other reasons preventing me from switching to that GPU permanently.
Is this a known problem with older ATI/AMD cards? Is there any other way to achieve what I am trying to do? Where would I check if that GPU even supports the “scaling mode” parameter?