Problem with 2 monitors in Arch

wheream1 · 2024-02-26 19:32:01

Main monitor is 165 Hz and second monitor is 60 Hz. Main monitor has DP cable and second has VGA cable but plugs in with HDMI adapter. When I turn on the second monitor my main monitor 165 Hz is lagging like I'm on 60 Hz. But my cursor still smooth. I saw problems like that, but the answer was to use Wayland instead X11. Can I avoid this?

 [123@myPC ~]$ neofetch
                   -`                    123@myPC 
                  .o+`                   ---------- 
                 `ooo/                   OS: Arch Linux x86_64 
                `+oooo:                  Host: MS-7C89 1.0 
               `+oooooo:                 Kernel: 6.7.6-arch1-1 
               -+oooooo+:                Uptime: 8 hours, 38 mins 
             `/:-:++oooo+:               Packages: 1177 (pacman) 
            `/++++/+++++++:              Shell: bash 5.2.26 
           `/++++++++++++++:             Resolution: 1920x1080 
          `/+++ooooooooooooo/`           DE: Plasma 5.27.10 
         ./ooosssso++osssssso+`          WM: KWin 
        .oossssso-````/ossssss+`         Theme: [Plasma], Breeze [GTK2/3] 
       -osssssso.      :ssssssso.        Icons: [Plasma], breeze-dark [GTK2/3] 
      :osssssss/        osssso+++.       Terminal: konsole 
     /ossssssss/        +ssssooo/-       CPU: Intel i5-10400F (12) @ 4.300GHz 
   `/ossssso+/:-        -:/+osssso+-     GPU: NVIDIA GeForce GTX 1650 
  `+sso+:-`                 `.-/+oso:    Memory: 4301MiB / 15931MiB 
 `++:.                           `-/+/
 .`                                 `/

Last edited by wheream1 (2024-02-26 22:34:01)

seth · 2024-02-26 20:28:27

The the environment to make the compositor sync to the 165Hz output.

wheream1 · 2024-02-26 20:51:16

seth wrote:

The the environment to make the compositor sync to the 165Hz output.

How can I do this?

seth · 2024-02-26 20:55:47

If your brains operates so fast that you can see 60Hz as lagging, you'll have absolutely no problems to figure that in no time.

wheream1 · 2024-02-26 21:00:17

seth wrote:

If your brains operates so fast that you can see 60Hz as lagging, you'll have absolutely no problems to figure that in no time.

I mean when my second monitor is off, my main monitor 165Hz works smoother

seth · 2024-02-26 22:06:59

https://download.nvidia.com/XFree86/Lin … ables.html
https://wiki.archlinux.org/title/Environment_variable

xrandr -q

Suspending the compositor should give you an idea whether this will help you.

wheream1 · 2024-02-26 22:29:55

seth wrote:

https://download.nvidia.com/XFree86/Lin … ables.html
https://wiki.archlinux.org/title/Environment_variable
xrandr -q
Suspending the compositor should give you an idea whether this will help you.

Okay, thanks

Last edited by wheream1 (2024-02-26 22:30:10)

Nikolai5 · 2024-02-27 10:39:03

seth wrote:

If your brains operates so fast that you can see 60Hz as lagging, you'll have absolutely no problems to figure that in no time.

That's a ridiculous comment. Anyone who has functioning senses can see the difference between 60 and 120+, it's night and day. I'd never go back to 60Hz.

seth · 2024-02-27 10:47:02

No, you see artifacts from multiple syncs and certaily if the source isn't capable of rendering reliably at the target rate.
No human being has ever demonstrated the ability to call differences north of certainly 80fps and above 60fps it's sketchy for most (better than just guessing but not nearly perfect) and impossible for many.

High fps outputs exist to hide shortcomings in the render chain, if you don't believe that, take a controlled test - yoz'll prtobably make some news.

andyturfer · 2024-02-27 11:41:02

I have a similar setup - a 165Hz monitor connected via DisplayPort, and a 60Hz monitor connected with HDMI. On X11, the 165Hz monitor is always janky (stuttery, laggy, not smooth - a generally bad user experience). The only thing I could do on X11 to reduce this was set the 165Hz monitor to 60Hz - things then worked a lot smoother (although I wasn't taking advantage of the beautiful 165Hz glory).

I'm now using Wayland because it does a much better job at handling multiple-monitor setups where the monitors have different refresh rates. I don't think X11 is capable of doing such things. It means I can't use some of the apps I've been using for years (like "simplescreenrecorder" and "flameshot"), but I'm now going to try "spectacle" instead. I still haven't tested screen sharing and video conferencing in Slack. I'm using KDE, so I figure in a worst case scenario, I can always quickly log out then log back in again using X11.

I'm really beginning to like Wayland now - it's fast, scrolling is buttery smooth (especially in Firefox), and there's much less hassle when setting up multiple monitors. Wayland + Firefox (on laptop with 165Hz panel) = smoothest browser scrolling I've ever seen (on any OS).

wheream1 · 2024-02-27 12:42:12

andyturfer wrote:

I have a similar setup - a 165Hz monitor connected via DisplayPort, and a 60Hz monitor connected with HDMI. On X11, the 165Hz monitor is always janky (stuttery, laggy, not smooth - a generally bad user experience). The only thing I could do on X11 to reduce this was set the 165Hz monitor to 60Hz - things then worked a lot smoother (although I wasn't taking advantage of the beautiful 165Hz glory).
I'm now using Wayland because it does a much better job at handling multiple-monitor setups where the monitors have different refresh rates. I don't think X11 is capable of doing such things. It means I can't use some of the apps I've been using for years (like "simplescreenrecorder" and "flameshot"), but I'm now going to try "spectacle" instead. I still haven't tested screen sharing and video conferencing in Slack. I'm using KDE, so I figure in a worst case scenario, I can always quickly log out then log back in again using X11.
I'm really beginning to like Wayland now - it's fast, scrolling is buttery smooth (especially in Firefox), and there's much less hassle when setting up multiple monitors. Wayland + Firefox (on laptop with 165Hz panel) = smoothest browser scrolling I've ever seen (on any OS).

Thank you so much for your reply. How can I switch to the Wayland? I read that I should install the "plasma-wayland-session" package and enable the DRM kernel mode setting.

V1del · 2024-02-27 13:04:50

Those are the things you need to do for that indeed. General note, please don't fully quote responses you're directly replying to and there hasn't been someone posting in between.

seth · 2024-02-27 21:18:10

Just ftr,

andyturfer wrote:

I don't think X11 is capable of doing such things.

It is. Your compositor might not. Your clients might not. The elements of the render chain might trip over each other.

Wayland doesn't really do any wonders here, it merely dictates the render loop.
Instead having the client, a compositor and possibly even the display server (depending on the driver and setting) trying to produce a synchronous output, the clients render into an offscreen buffer, hand that to the compositordisplayserver and that integrates it into the output.
There're pot. downsides (eg. video players trying to to a reverse pulldown seem to struggle?) but the process is obviously more streamlined.
You /can/ do that w/ X11, but it's more effort to setup because you've to look at many things and prevent them from doing stupid things.

The main thing you want to do in an office environment, given your driver allows that, is to enable triple buffering, because it can hide many of the conflicts in an unorganzied render chain.
(It'll also give you 1 frame latency which your average pro-g4m0r will decry as pure evil and the reason why they get fragged so much

Though wrt

the 165Hz monitor is always janky (stuttery, laggy, not smooth

- while 60fps on 165Hz will run at 55fps and occasionally jump to 90fps (cutting one frame in half) and you'll probably have an easier life w/ a 60/120Hz combo, many of the 16xHz outputs are actually https://wiki.archlinux.org/title/Variable_refresh_rate and if that doesn't properly work, the output might generally refresh far too rarely - depends on what you actually see. As pointed out: the render chain on "modern X11 desktops"™ is complicated and every stage can drop the ball here.

Just in case you ever need to return to X11 - there's hope

andyturfer · 2024-02-29 12:28:26

Thanks - this is very interesting. I still dip in to X11 every now and then (to use some of my favorite screen capturing apps, like "simplescreenrecorder"). When I have more time I'll do a deeper dive into X11 with multiple monitors running at different refresh rates. I just love the way Wayland seems to "just work" out of the box Kinetic scrolling in Firefox with Wayland blew my mind! So smooth, so responsive. I know this can be configured in X11 too, but it's not the same - in X11 scrolling a long web page "micro-stutters" every now and then.

seth wrote:

... It'll also give you 1 frame latency which your average pro-g4m0r will decry as pure evil and the reason why they get fragged so much ...

I'm not a gamer, but I love "smooth and responsive", especially when it comes to scrolling. Every time I experience a "micro-stutter" while scrolling, it feels like someone is poking a pin in my eyeball!

FYI: Many years ago, Intel reversed engineered the "Apple iPhone user-experience", and concluded its success (from a hardware point of view) was down to 2 things:

A consistent refresh rate on the user interface (60Hz at the time)
Fast response time for touch events (can remember the number now, but basically the page followed your finger like a magnet)

When I use Wayland on a laptop with a 165Hz monitor, I feel like I've living in the future

But yeah, will definitely spend some time trying to get X11 performing the same...

andyturfer · 2024-02-29 12:37:31

wheream1 wrote:

How can I switch to the Wayland? I read that I should install the "plasma-wayland-session" package and enable the DRM kernel mode setting.

Not sure about the "DRM kernel mode setting". I have an AMD laptop (both the iGPU and dGPU are AMD). All I had to do was install "plasma-wayland-session", and then select "Wayland" on the greeter (login) screen. You can easily switch between the two at login.

I haven't tried Wayland with an Nvidia GPU yet, but I have an old laptop that has an Nvidia GTX 1660TI, so may have to dust it off and give it a try.

Last edited by andyturfer (2024-02-29 12:38:46)

wheream1 · 2024-02-29 16:00:00

I didn't on "DRM kernel mode setting" to avoid issues, but when I choose Wayland I have black screen and mouse and nothing change.

Last edited by wheream1 (2024-02-29 16:02:17)

V1del · 2024-02-29 16:03:29

This isn't optional on a nvidia GPU, you need to enable it. On amdgpus it's implicitly enabled by default, on nvidia you need to add "nvidia_drm.modeset=1" to your kernel parameters.

wheream1 · 2024-02-29 16:39:55

Can it provide any issues with boot system or something? And to enable it just write in GRUB

 GRUB_CMDLINE_LINUX_DEFAULT=“nvidia_drm.modeset=1”

update GRUB and reboot ? Or maybe do this with modprobe.d?

seth · 2024-02-29 16:41:41

Or maybe do this with modprobe.d?

modprobe.d will suffice for wayland but the kernel parameter will disable the simpledrm device and guarantee that you're actually using the nvidia driver.

Arch Linux

#1 2024-02-26 19:32:01

Problem with 2 monitors in Arch

#2 2024-02-26 20:28:27

Re: Problem with 2 monitors in Arch

#3 2024-02-26 20:51:16

Re: Problem with 2 monitors in Arch

#4 2024-02-26 20:55:47

Re: Problem with 2 monitors in Arch

#5 2024-02-26 21:00:17

Re: Problem with 2 monitors in Arch

#6 2024-02-26 22:06:59

Re: Problem with 2 monitors in Arch

#7 2024-02-26 22:29:55

Re: Problem with 2 monitors in Arch

#8 2024-02-27 10:39:03

Re: Problem with 2 monitors in Arch

#9 2024-02-27 10:47:02

Re: Problem with 2 monitors in Arch

#10 2024-02-27 11:41:02

Re: Problem with 2 monitors in Arch

#11 2024-02-27 12:42:12

Re: Problem with 2 monitors in Arch

#12 2024-02-27 13:04:50

Re: Problem with 2 monitors in Arch

#13 2024-02-27 21:18:10

Re: Problem with 2 monitors in Arch

#14 2024-02-29 12:28:26

Re: Problem with 2 monitors in Arch

#15 2024-02-29 12:37:31

Re: Problem with 2 monitors in Arch

#16 2024-02-29 16:00:00

Re: Problem with 2 monitors in Arch

#17 2024-02-29 16:03:29

Re: Problem with 2 monitors in Arch

#18 2024-02-29 16:39:55

Re: Problem with 2 monitors in Arch

#19 2024-02-29 16:41:41

Re: Problem with 2 monitors in Arch

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