144p video choppy in 5K monitor

User Support
1

Typing text or browsing web page is smooth but watching video is choppy even with worst quality 144p.

If I decrease the resolution to 3440x1440 in display setting, 1080P video can be smooth, but I prefer not to do it because in 3440x1440 text is vague.

CPU:

  • 4 Cores 8 Threads
  • Base Frequency 2.9 GHz
  • Intel® HD Graphics 630

Intel® HD Graphics 630 can handle two 4K monitors simultaneously theoretically via Thunderbolt and DisplayPort. Pixels of two 4K are greater than 5K, so it should can handle 5K and there is successful case in reference [1].

The monitor is connected via Thunderbolt line.

CPU usage is only 15% in APP VM that playing video and 5% in DOM0 when watching local 144p video in 5K resolution. Is there any way to let DOM0 put more CPU on rendering and will this be helpful?

Qubes OS version R4.0

5K is 5120x2160, 4K is 3840x2160.

Possible solutions

GPU pass through

The dedicated GPU of the laptop is Nividia which is harder to pass through according to posts on forum, can we pass through the integrated Intel GPU instead?

If the integrated GPU can’t satisfy our needs, can we pass through eGPU?

Decrease resolution

Decrease resolution when watching video and restore it when doing others.

Use another PC

Use another PC with same keyboard, mouse and monitor and use KVM switch to switch those input devices.

Reference

  1. Intel HD 630 graphics support for HP Z27q 27 inch 5k monitor
2

Did you try this?

3

Following Video RAM adjustment for high-resolution displays:

  • My gui-videoram-min is already greater than required

Create /etc/X11/xorg.conf.d/20-intel.conf

Section "Device"
  Identifier "Intel Graphics"
  Driver "i915"
  Option "TripleBuffer" "true"
EndSection

according to Intel graphics - ArchWiki

i915 found by sudo lspci -k | grep -EA3 'VGA|3D|Display' - How to fix video tearing in Linux (with Intel graphics).

Option "TripleBuffer" "true"

This option forces X to perform all rendering to a backbuffer prior to updating the actual display … This option is disabled by default, but you may want to enable it. This means more video memory used, but you should also have a smoother playback.

I don’t know how to judge whether it’s applied. I open video in a new disp VM, seems doesn’t change.

log

I think there is no error in log, the output below is empty

cat /var/log/Xorg* | grep software

$ cat /var/log/Xorg* | grep render
Intel(0): Direct rendering: DR12 DR13 enabled

If you are experiencing this issue, you will see extremely slow graphics updates. You will be able to watch the screen and elements paint slowly from top to bottom. You can confirm this is the issue by looking for a line similar to the following in your /var/log/Xorg.0.log file:

[   131.769] (EE) AIGLX: reverting to software rendering

You might face issues when playing video, if the video is choppy instead of smooth display this could be because the X server doesn’t work. You can use the Linux terminal (Ctrl-Alt-F2) after starting the virtual machine, login. You can look at the Xorg logs file. As an option you can have the below config as well present in /etc/X11/xorg.conf.d/90-intel.conf, depends on HD graphics though -

4

I see that you updated the above post. Some people, including some core developers, are interacting with this forum via email. They do not receive the edits made after 10 minutes. For this reason, it’s better to make a new post, not update the old one (and/or use quotations like I do here).

Here is your edited post for them
5

I didn’t know that, I will create new post next time

1 Like
6

After adding 20-intel.conf and reboot, the screen is black after inputting disk password? How can I delete the 20-intel.conf file? Is there any recovery-mode?

7

After rebooting again, can display but stuck after “Started Command Scheduler”.

8
9

I am not sure if “choppy” is the same as “flickering”, but if it is maybe you should try to add i915.enable_psr=0 as kernel parameter.

10

My problem is not flickering

2048×1536 473 KB
.
It’s screen tearing, you can example video here.

1 Like
11

Can anyone indicate what is the error of the config?
Is there any way to check config before applied?
Can I apply it without logout?

12

Update to

/etc/X11/xorg.conf.d/20-intel.conf**

Section "Device"
  Identifier "Intel Graphics"
  Driver "intel"
  Option "TearFree" "true"
  Option "TripleBuffer" "true"
EndSection

from

13
  • Can’t display before because of Driver "i915"
  • Can’t distinguish external monitor after adding 20-intel.conf and logout to enable it
14

Does this need to match your GPU brand/driver? I’m running a GTX3060Ti @ 5K and my whole PC lags/skips if there is multimedia content or animations. I went down the nvidia driver install path, but learned that wasn’t correct. (BTW, installing Qubes in this state is a painful experience). Performing a kernel update helped tremendously however skipping is getting annoying.

15

I think this can only be used for Intel iGPU as it’s only documented in Intel doc. And I gave up to resolving this problem now, I prefer to wait until GPU passthrough is mature in 4.1.