2 screens, different DPI

[charlycop]

Hi,

I have 2 screens, one very high DPI, I double the DPI on cinnamon, and then other one is a classical 1080p screen.

How can I setup double DPI on 1 screen, and normal DPI on the other screen

I tried xrandr, but no success to get the different scaling on the two different screens.

Thanks.

[charlycop]

"HiDPI" MODE


"Normal"

[palytoxin]

same problem.

Code: Select all

~ » xrandr --listmonitors 
Monitors: 2
 0: +*eDP-1 3840/309x2160/174+0+0  eDP-1 (thinkpad x1c7 14'1inch)
 1: +HDMI-1 1920/518x1200/324+3840+0  HDMI-1 (24 inch)

cinnamon can't setting diff dpi for two monitor.
and

Code: Select all

xrandr --output HDMI-1 --scale 2x2 --mode 1920x1080

The primary monitor mouse keeps blinking

[absque fenestris]

...
I have 2 screens, one very high DPI, I double the DPI on cinnamon, and then other one is a classical 1080p screen.
...

Hi
I have such a system setting in Mint Cinnamon:

1. Laptop = 3000 x 2000 (native) set as 1500 x 1000 at 200% Hi-DPI
2. External monitor = 1920 X 1200 set as 1920 x 1200 (native)

This was (and is) possible with the > Display > System Settings in Cinnamon.

Linux Mint Cinnamon offered me exactly this setting both in live mode and in the loaded state: I simply didn't have to change the default settings.

I'm surprised that it doesn't work for you with Mint Cinnamon.

[absque fenestris]

...
cinnamon can't setting diff dpi for two monitor.
...

Not yours - mine does ...

[Oliver-Queen]

How can I setup double DPI on 1 screen, and normal DPI on the other screen

First you're going to want to get your displays name. You can do this by opening display in your LM menu, then all displays will show their internal name on the top left. Or on the bottom inside the preview window.

You can also find this information by putting the following in your terminal:

Code: Select all

xrandr | grep connected | grep -v disconnected | awk '{print $1}'

But this will only show you the names of the displays without any identifying qualities so it's easier to use display in settings.

Now, once you have your displays name, you'll want to use

Code: Select all

xrandr (Display Name Here) --scale (Number to scale)x(Number to scale)

For example, if opening Display in Settings shows that the laptop display is eDP-1 and your second monitor as DP-1, then you can use:

Code: Select all

xrandr eDP-1 --scale 0.5x0.5

To make the display twice as large (it halves the pixels rendered so the image must be doubled to fit, effectively zooming by double.) <I'm not sure this is why it works but this is what I assume with my limited knowledge of programming.

Now, there is something to be made aware of. Once you do this your GUI will show the monitor you made smaller as being spaced away from your second monitor.


So what you need to do is in the Display GUI stick the two displays together. Once you do that it'll make the display you shrunk original size again, so the displays will first look normal, and then overlap like this:



Finally, run the same code in your terminal, in my case:

Code: Select all

xrandr eDP-1 --scale 0.5x0.5

It'll shrink the monitor again and it'll be properly positioned since the displays are already overlapping, once it's shrunken it'll be perfectly aligned.


Something to note about this method:
This method doesn't use UI scaling to work, it instead uses Fractional Scaling. UI Scaling is intentionally global, as you can see here:


Don't worry, your display won't be as illegible as that last screenshot, that's because I had to screenshare to get a friend to take the screenshot for me since the pop up would go away when I would do the screenshot shortcut of shift+printscreen or just printscreen.

Hope this helped!