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Comment by omegabravo | Hacker News Reader

I have 2x 24" monitors on Ubuntu 18.04.03 with a Radeon RX 580

I can't watch a video on Youtube without substantial tearing on Firefox or Chrome. I've followed close to 20 guides and tried a number of drivers which all fail provide any benefit.

Running glxgears will run at 7400FPS, with minor tearing. My monitors don't have FreeSync or whatever it's called since they're pretty old (over 10 years).

Since most guides are as helpful as "type this into a console" - I haven't learnt anything while trying these fixes.

edit: I tried to install the newest drivers (19.50), and they fail to install with build errors

since I had to uninstall the old ones (19.20) I'm now running Polaris10? drivers by accident, and the tearing issue seems to have disappeared. I have no idea if these are less performant, but they are sufficient for my needs.

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Switch to Wayland, your issue is that Xorg is not tear free by default and Ubuntu has chosen to stick with this legacy stack in 18.04: https://www.omgubuntu.co.uk/2018/01/xorg-will-default-displa...

Tearing issues tend to be problems of the application, compositor, or Xorg. Nothing the driver can do much about, unfortunately. Xorg in particular is pretty bad at tearing with multi-monitor setups.

Some DDX drivers handle tearing (implementing vsync). Tearing is basically not a problem at all on Wayland compositors since the spec addresses it directly (from what I understand)

Switch to Wayland or just enable TearFree on Xorg, something like: `xrandr --output DisplayPort-0 --set TearFree on` of course you have to adjust to your output (`xrandr --props`).

My condolences. On Nvidia there is a Full Composition Pipeline option in Nvidia driver settings which gets rid of vsync issues. It's odd it's not on by default.

Wow, that's good to know! How do you turn it on?

(I don't see an option for it in the Nvidia X Server Settings app.)

Nvidia X Server Settings app -> X Server Display Configuration -> Advanced... -> Force Full Composition Pipeline

Note, it is not saved during a reboot unless you click 'Save to X Configuration File' and then save to /etc/X11/xorg.conf for most distros.

Also, many distros have partial v-sync of some sort on. For most it isn't noticeable, but for many desktops it causes the screen to run at an effective 59 instead of 60fps (or that is what it looks like to me, non-scientific here), so it can be beneficial to look up how to turn off vsync on your distro. Eg, I'm on Mint so for me it's General Settings -> VSync method -> None. For most people, this is not a noticeable change.

Thank you for explaining it so clearly.

I have a 580. Have you tried turning on the in-driver vsync option? AMD's implementation of it seems the best to me out of cards I've tried. You can turn it on while X is running easily using xrandr to see if it helps:

https://wiki.archlinux.org/index.php/AMDGPU#Tear_free_render...

Look at your compositor, I've fixed this in KDE by enabling Full Screen Repaints under vsync options.

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