Display issues

Hello to all!
I am a new ZorinOS (and also linux) user, and recently installed ZorinOS lite. My laptop's performance is boosted but there is an issue that I would like a solution with. When I connect my device to the the TV from an HDMI cable, I observe that I cannot tick mirror display in the display options. As a result, one of the two monitors will bug and have severe issues (freeze and be disproportionate). I must close my primary monitor in order to stop the problems. However, there is another issue that occurs: I observe that many videos that are played from the internet are really laggy and I cannot watch anything.

My two questions are:
a) Is there any way that I can tick mirror display (I tried to change the resolutions it didn't seem to help).
b) How can I watch videos via internet without any problem? (I tried to change the freeze rate it didn't help)

I should mention that (obviously) I do not have any knowledge in programming and using linux so please keep this in mind if it is possible.

Thank you in advance!

I think star treker might be able to help you out on this one. One solution I read on here was to boot the notebook first then connect the HDMI cable to the Notebook after turning on the TV.

I read that in a post too, I tried it but it did not work. I should mention that I also used
xrandr --output HDMI-0 --auto --same-as (device screen)
but the display wasn't mirrored, my main device monitor had just a proportion of the TV screen, not the same.
If someone knows any other possible solution to this I would be grateful.

Hello to all!
I'd like to inform the forum that I believe I found a solution to this. For anyone that may have the same problem this is what I found:

xrandr --output (device screen name) --mode 1366x768 --scale 1x1 --output HDMI-0 --same-as (device screen name) --mode 1920x1080 --scale 0.711x0.711

This helped to make proportionate the laptop and TV screen. If someone has the same resolutions in his device and TV as mine the 0.711 scale will work. However, I do not know what scale should be used if tthere are different resolutions from mine.

Hello to all!
I'd like to inform the forum that I believe I found a solution to this. For anyone that may have the same problem this is what I found:

xrandr --output (device screen name) --mode 1366x768 --scale 1x1 --output HDMI-0 --same-as (device screen name) --mode 1920x1080 --scale 0.711x0.711

This helped to make proportionate the laptop and TV screen. If someone has the same resolutions in his device and TV as mine the 0.711 scale will work. However, I do not know what scale should be used if tthere are different resolutions from mine.

Well done you!

And many thanks for sharing!

Yes, finding out the native resolution of both the sending and receiving device screens is a good starting point.

If xrandr has those two values as standard, use them as suggested.


If one/both does not exist, create it in line with my previous posting - there are several copies of it in the timeline.

Here is one - have a quiet read through and explore:

viewtopic.php?f=5&t=13594

Thank you Finston for the info.

I would like to ask if there is a way to run automatically the "display mirroring command" when the HDMI is plugged in. I believe this will also make things easier as one would not need to run it every time.