Arch Linux

Staubsauger

Member

Registered: 2015-01-30

Posts: 9

Lags when using hdmi out

Hi,
I got following problem: when I run a video or a game on my laptop, everything is working fine (e.g. youtube or retro-games using retroarch). But when I do the same, using hdmi-out on my tv (tested two different ones) or an other monitor, I get a stutter every minute or two. This makes playing games on external TV unplayable and watching videos is also not that much fun.
I tried to use kms driver instead of xf86-video-intel. But the lags remained. My laptop screen is full hd. One of the tv's I tested on is also full hd, the other one is only 720p. The monitor is also full hd. But on all three devices it's the same...

 CPU:
  Info: dual core model: Intel Core i5-7300U bits: 64 type: MT MCP cache:
    L2: 512 KiB
  Speed (MHz): avg: 796 min/max: 400/3500 cores: 1: 800 2: 800 3: 800
    4: 785
Graphics:
  Device-1: Intel HD Graphics 620 driver: i915 v: kernel
  Device-2: Acer Integrated Camera type: USB driver: uvcvideo
  Display: x11 server: X.org 1.21.1.3 driver: loaded: modesetting
    resolution: <missing: xdpyinfo>
  OpenGL: renderer: Mesa Intel HD Graphics 620 (KBL GT2) v: 4.6 Mesa 21.3.5

Thanks in advance !

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,079

Re: Lags when using hdmi out

Differing refresh rates? Are you using a compositor, which? Do things improve if you disable the compositor? One big problem of the way xorg works is that you can only reliably sync on a single output which will likely be the default display ergo your laptop. Do you close the lid/disable the laptop screen during this?

Technically xorg's modesetting driver got a new option that should help with this. See https://man.archlinux.org/man/modesetting.4#Option~8 which you can set with e.g. /etc/X11/xorg.conf.d/20-modesettingFix.conf

Section "OutputClass"
     Identifier "intel"
     Driver "modesetting"
     MatchDriver "i915"
     Option "AsyncFlipSecondaries" "on"
EndSection

if that doesn't help you might want to give a Wayland session a try since this is one of the problems that can't properly be fixed on Xorg and one of the reasons behind working on Wayland.

Maybe also more generally so we have more to go by, what's your

xrandr -q

and a Xorg log while reproducing this?  https://wiki.archlinux.org/title/Xorg#General
https://wiki.archlinux.org/title/List_o … n_services

Last edited by V1del (2022-02-08 15:41:23)

Staubsauger

Member

Registered: 2015-01-30

Posts: 9

Re: Lags when using hdmi out

Hi,
thanks for your answer. The problem was still present with <Option "AsyncFlipSecondaries" "on">. I was testing with the laptop screen turned off by the way. I'm pretty sure it has to do with the different refresh rates...
I ended up switching to kde with wayland and now it works fine. I will test if its also working with kde and x11. But maybe its a good time to switch.
Thanks for your help.