Xfce Forum

QTaKs

Member

Registered: 2023-08-12

Posts: 1

Stutters in Xfce with vulkan app launched

Hello!

I have laptop with prime graphics (AMD igpu + Nvidia dgpu) with Archlinux installed (everything is up to date). Main (laptop build-in) screen connected to igpu, external monitor to dgpu.
The problem: in Hybrid mode (X on igpu + offloading to dgpu), then I launch vulkan app (for example, vkcube or dxvk game) with second monitor connected, I experience graphical stutters (sound continues to play). Screens (whole graphical system with mouse cursor) can be frozen from 1 to 10 seconds.
This situation can be easily triggered by dragging figures in LibreOffice Draw.

The stutters does not occur then running Xorg on Nvidia gpu, but in this mode are some other problems.
At first I think that it is another nvidia prime problem, but in KDE Plasma there are no stutters!

That have done:

• Launched Xfce without display manager (SDDM)

• Disabled various parts of Xfce (panel, themes and etc)

• Tried this, like in other thread suggested

• Turning prime sync on/off

• Hybrid mode with[out] optimus manager

Some tests with other DEs:

• KDE + KWin = no stutters

• KDE + openbox = no stutters

• KDE + XFWM = no stutters

• Xfce4 + XFWM = stutters (for mine profile)

• Xfce4 + XFWM = stutters (for new user with default config)

• Xfce4 + XFWM = stutters (in liveCD archiso)

• Xfce4 + openbox = stutters

• Xfce4 + Kwin = stutters

• Openbox = stutters

• LXQt + openbox = stutters

• LXQt + i3 = stutters

• LXQt + KWin = stutters

• awesome = stutters

Also tried using picom for composing - no changes.

Seems like, there is some workaround done in KDE session, so there are no stutters.

In Xorg logs after stutters only lines like this:

client bug: timer event8 debounce: scheduled expiry is in the past (-1507ms), your system is too slow

or this:

event8  - UGREEN  Mouse: SYN_DROPPED event - some input events have been lost.

That is about Xorg looses mouse input because of stutters.
journalctl output has nothing about stutters

There is topic on nvidia forum with similar problem, but they have problems with KDE, that I does not have.
Seems like this is the problem of wrong working reverse PRIME, but again - I have no stutters in KDE.

I am using official proprietary (tested with open modules) Nvidia driver

Any help for further investigating?

Last edited by QTaKs (2024-07-06 07:54:04)

eriefisher

Member

From: ON, Canada

Registered: 2008-10-25

Posts: 528

Re: Stutters in Xfce with vulkan app launched

I have an old laptop(2015 era?) with a AMD Thames graphics chip so nothing fancy at all. When I run vkcube it's very smooth and I can still do other things while it's running and it doesn't stutter.

---

Siduction
Debian Sid
Xfce 4.18