[SOLVED] Weird artefacts on one of my screens

kyngs · 2022-10-16 08:01:58

One of my screens has weird artifacts (like if the contrast or smth like that was wrong). Both of them are the same monitor models and are set to default settings. This appears to be related to my Arch installation because it seems to work just fine under a live-booted Fedora. Perhaps somehow resetting the settings would work?
Photos (I actually needed to take a photo of them, because it is not visible when print-screening): https://imgur.com/a/Kxllehr
I use proprietary Nvidia drivers with Xorg and KDE
EDIT: It seems that this issue does not appear on the SDDM login screen

Last edited by kyngs (2022-10-19 15:34:55)

seth · 2022-10-16 08:12:33

It kinda looks like dithering, please post your xorg log and in nvidia-settings check the monitor settings specifically the dithering ones (digital vibrance might cause banding but the photo doesn't look that way - the quality isn't good enough to be sure, though)

kyngs · 2022-10-16 08:22:50

seth wrote:

It kinda looks like dithering, please post your xorg log and in nvidia-settings check the monitor settings specifically the dithering ones (digital vibrance might cause banding but the photo doesn't look that way - the quality isn't good enough to be sure, though)

Hi, thanks for your reply.
I have no idea how to upload files here, so I pasted my Xorg log to textbin: https://textbin.xyz/?400fc82fd47268bc#9 … YSKpPSoW7X
Both monitors in Nvidia settings have Dithering enabled.
Btw, the problematic monitor is DP-2

Last edited by kyngs (2022-10-16 08:24:26)

seth · 2022-10-16 08:42:56

I'd start by disabling dithering.
And since the outputs are equal and seem 120Hz capable, also post the output of "xrandr -q" and try to run them at 60Hz.

kyngs · 2022-10-16 08:50:02

seth wrote:

I'd start by disabling dithering.
And since the outputs are equal and seem 120Hz capable, also post the output of "xrandr -q" and try to run them at 60Hz.

Disabling dithering only makes it worse, interestingly, setting it to 60hz makes the issue barely visible, but it is still there. However, I am not planning to run my 240hz screens at 60hz.
xrandr -q: https://textbin.xyz/?aba4d4bd23be013b#F … TSuhDDnZ2X

seth · 2022-10-16 09:02:38

Sounds like a signal issue. Did you move both outputs to 60Hz?
Does it happen if you attach only one output (either)?
What happens if you swap the cables?
Are there more than those two external jacks?
Is an usb3/DP connection involved?

kyngs · 2022-10-16 09:08:12

seth wrote:

Sounds like a signal issue. Did you move both outputs to 60Hz?
Does it happen if you attach only one output (either)?
What happens if you swap the cables?
Are there more than those two external jacks?
Is an usb3/DP connection involved?

I did try setting it to 60 Hz. As described in my previous reply, it almost disappeared.
I've tried swapping the cables.
Yes, I've tried using different ports.
I am not sure what usb3/DP connection means. EDIT: Do you mean USB to DP? That is not the case.

But I doubt that this is an HW issue because it works fine under Fedora.

Last edited by kyngs (2022-10-16 09:09:34)

seth · 2022-10-16 09:16:07

I did try setting it to 60 Hz.

seth wrote:

Did you move both outputs to 60Hz?

I've tried swapping the cables.

What was the result?

seth also wrote:

Does it happen if you attach only one output (either)?

I am not sure what usb3/DP connection means.

There're USB3 / DP hybrid outputs that will toggle depending on what you plug there. (usually indicated w/ an icon next to them)

But I doubt that this is an HW issue because it works fine under Fedora.

On X11 and w/ 240Hz?

What happens if you suspend the compositor (shift+alt+f12)
But the symptoms so far (nvidia enabling dithering, frequency dependent, combined signal payload tests pending) very much indicate a signal issue, the only question being "where".

kyngs · 2022-10-16 09:44:05

seth wrote:

I did try setting it to 60 Hz.

seth wrote:

Did you move both outputs to 60Hz?

Yes, with the same result as described earlier.

I've tried swapping the cables.

What was the result?

It's the same as before. I've also tried swapping them on the monitor side, with no success.

seth also wrote:

Does it happen if you attach only one output (either)?

Yep

I am not sure what usb3/DP connection means.

There're USB3 / DP hybrid outputs that will toggle depending on what you plug there. (usually indicated w/ an icon next to them)

I think that's not the case

But I doubt that this is an HW issue because it works fine under Fedora.

On X11 and w/ 240Hz?

I did not realize that Fedora is now defaultly running on Wayland, after switching to X11 I still don't see the issue.

What happens if you suspend the compositor (shift+alt+f12)

Still the same

seth · 2022-10-16 09:57:59

I'd assume that the Fedora live system also runs on nouveau?
Do you get the same effect w/ arch+nouveau?
If not, it might be some power saving issue and ramping up the GPU/VRAM frequencies be necessary.

kyngs · 2022-10-16 10:55:37

seth wrote:

I'd assume that the Fedora live system also runs on nouveau?
Do you get the same effect w/ arch+nouveau?
If not, it might be some power saving issue and ramping up the GPU/VRAM frequencies be necessary.

I guess that fedora live runs nouveau, gonna try it on my system in a few hours.

kyngs · 2022-10-16 19:47:14

So, I didn't manage to get nouveau working. So i thought I would try to install a new installation on a separate partition, to see whether the issue persists. Unfortunately while partitioning my drive, I've managed to brick the installation (it doesn't go past sddm login). The data seems intact, so most likely tomorrow I will back it up and reinstall Arch. I hope that the issue won't persist.

seth · 2022-10-16 20:02:31

So, I didn't manage to get nouveau working.

Either removing the nvidia driver or un-blacklisting nouveau and blacklisting nvidia should do?

(it doesn't go past sddm login)

Do you have a journal for that boot?
I don't think something is bricked there (unless you created a new partition and shedded the FS in that pursuit)

kyngs · 2022-10-16 20:08:01

So, I didn't manage to get nouveau working.
Either removing the nvidia driver or un-blacklisting nouveau and blacklisting nvidia should do?

I didn't find the module blacklisted anywhere. Or at least not in common places. Even when manually injecting it via modprobe and restarting sddm, there was some issue with x config.

(it doesn't go past sddm login)
Do you have a journal for that boot?
I don't think something is bricked there (unless you created a new partition and shedded the FS in that pursuit)

Sddm freezes when I attempt to log in. I can switch to another tty, so I will check the journal.

seth · 2022-10-16 20:20:08

Did you look at /usr/lib/modprobe.d/nvidia-utils.conf ?

kyngs · 2022-10-17 13:30:19

seth wrote:

Did you look at /usr/lib/modprobe.d/nvidia-utils.conf ?

Oof! It appears that this file exists even though I uninstalled the Nvidia driver. Gonna try nouveau once again.

Btw, after consulting the journal, I've found out that the partition was full (even though GParted reported 50GB left), so I've expanded it and it boots now.

kyngs · 2022-10-17 13:32:11

So, not only does the PC boot 3 times as fast, the issue has now disappeared. Perhaps I should file a bug report?

EDIT: It boots stupidly fast, I hate Nvidia so much.

Last edited by kyngs (2022-10-17 13:34:02)

seth · 2022-10-17 13:54:49

/usr/lib/modprobe.d/nvidia-utils.conf is part of nvidia-utils.
Do you have a system journal for an older boot (eg. "sudo journalctl -b -4" for the 4th last one) w/ the binary nvidia driver?

kyngs · 2022-10-17 14:03:54

seth wrote:

/usr/lib/modprobe.d/nvidia-utils.conf is part of nvidia-utils.
Do you have a system journal for an older boot (eg. "sudo journalctl -b -4" for the 4th last one) w/ the binary nvidia driver?

I'm back on prop. drivers, here's the journal for the last boot: https://textbin.xyz/?a4bfe02e63ee5382#a … ZJh8Y6R9Bk

seth · 2022-10-17 14:20:25

You're reaching the graphical target after 5 and your user session after 10 seconds.
There're no obvious errors/problems but if you're still facing the original or other problems, try the LTS kernel.
The 6.x kernels changed the ACPI API and wrt https://bbs.archlinux.org/viewtopic.php?id=280528 this might prevent the GPU from fully powering up - resulting in artifacts and overall slowness…

kyngs · 2022-10-17 14:21:58

seth wrote:

You're reaching the graphical target after 5 and your user session after 10 seconds.
There're no obvious errors/problems but if you're still facing the original or other problems, try the LTS kernel.
The 6.x kernels changed the ACPI API and wrt https://bbs.archlinux.org/viewtopic.php?id=280528 this might prevent the GPU from fully powering up - resulting in artifacts and overall slowness…

I have already tried the LTS kernel, with no success. I do not observe slower performance. Or at least not in games.

I however have not used the LTS drivers. Gonna try

EDIT: The issue still persists with the LTS kernel and drivers.

Last edited by kyngs (2022-10-17 14:27:48)

kyngs · 2022-10-18 16:33:59

So no idea?

seth · 2022-10-18 19:36:33

Sorry, didn't see the edit.
It doesn't seem to be a kernel regression but related to the nvidia driver then (so not with nouveau)?
You could try to for the GPU to operate in performance mode in nvisia-settings and see whether this makes it go away.

If no (and it's not a performance/power thing) It might be the audio channel, https://bbs.archlinux.org/viewtopic.php?id=253258 (I'm at hand not sure whether the HDMI module does this, but we'll see)

walmartshopper · 2022-10-19 05:23:29

I have something similar going on, might be the same issue. I have 4 monitors. Two of them look fine, but two have similar color banding where it looks like they are running a low color depth. However it's only noticeable in certain areas. Most noticeable is the blur effect under a transparent konsole window. But also the gradients on title bars have noticeable banding, and sometimes the shadows under windows. It happens with compositing both on and off. All monitors are set to RGB color space, full range color, dithering off.

All 4 monitors are 1440p. The ones that look normal are 170hz on displayport and 60hz on HDMI. The two that look wrong are both 60hz over displayport. Changing these to 75hz does not fix it.

I upgraded to kernel 6.0, nvidia 520.56.06, and plasma 5.26 all at the same time, so I'm not sure what caused it.

UPDATE: Downgrading kernel to 5.15 did not help. And I noticed the issue happening on SDDM login when the blur effect kicked in, so I knew it wasn't kwin. I switched to nvidia-vulkan 515.49.19 and the problem went away, so it's definitely a bug in the new nvidia 520.56.06 driver.

Last edited by walmartshopper (2022-10-19 05:47:39)

kyngs · 2022-10-19 06:04:09

walmartshopper wrote:

I have something similar going on, might be the same issue. I have 4 monitors. Two of them look fine, but two have similar color banding where it looks like they are running a low color depth. However it's only noticeable in certain areas. Most noticeable is the blur effect under a transparent konsole window. But also the gradients on title bars have noticeable banding, and sometimes the shadows under windows. It happens with compositing both on and off. All monitors are set to RGB color space, full range color, dithering off.
All 4 monitors are 1440p. The ones that look normal are 170hz on displayport and 60hz on HDMI. The two that look wrong are both 60hz over displayport. Changing these to 75hz does not fix it.
I upgraded to kernel 6.0, nvidia 520.56.06, and plasma 5.26 all at the same time, so I'm not sure what caused it.
UPDATE: Downgrading kernel to 5.15 did not help. And I noticed the issue happening on SDDM login when the blur effect kicked in, so I knew it wasn't kwin. I switched to nvidia-vulkan 515.49.19 and the problem went away, so it's definitely a bug in the new nvidia 520.56.06 driver.

I'm glad that I'm not the only one having the issue. I can see it in the exact same spaces as you describe. It gets progressively worse the higher refresh rate I set, which is maybe why it isn't as visible on your machine.
How did you get the 515 driver running on kernel 6?

Arch Linux

#1 2022-10-16 08:01:58

[SOLVED] Weird artefacts on one of my screens

#2 2022-10-16 08:12:33

Re: [SOLVED] Weird artefacts on one of my screens

#3 2022-10-16 08:22:50

Re: [SOLVED] Weird artefacts on one of my screens

#4 2022-10-16 08:42:56

Re: [SOLVED] Weird artefacts on one of my screens

#5 2022-10-16 08:50:02

Re: [SOLVED] Weird artefacts on one of my screens

#6 2022-10-16 09:02:38

Re: [SOLVED] Weird artefacts on one of my screens

#7 2022-10-16 09:08:12

Re: [SOLVED] Weird artefacts on one of my screens

#8 2022-10-16 09:16:07

Re: [SOLVED] Weird artefacts on one of my screens

#9 2022-10-16 09:44:05

Re: [SOLVED] Weird artefacts on one of my screens

#10 2022-10-16 09:57:59

Re: [SOLVED] Weird artefacts on one of my screens

#11 2022-10-16 10:55:37

Re: [SOLVED] Weird artefacts on one of my screens

#12 2022-10-16 19:47:14

Re: [SOLVED] Weird artefacts on one of my screens

#13 2022-10-16 20:02:31

Re: [SOLVED] Weird artefacts on one of my screens

#14 2022-10-16 20:08:01

Re: [SOLVED] Weird artefacts on one of my screens

#15 2022-10-16 20:20:08

Re: [SOLVED] Weird artefacts on one of my screens

#16 2022-10-17 13:30:19

Re: [SOLVED] Weird artefacts on one of my screens

#17 2022-10-17 13:32:11

Re: [SOLVED] Weird artefacts on one of my screens

#18 2022-10-17 13:54:49

Re: [SOLVED] Weird artefacts on one of my screens

#19 2022-10-17 14:03:54

Re: [SOLVED] Weird artefacts on one of my screens

#20 2022-10-17 14:20:25

Re: [SOLVED] Weird artefacts on one of my screens

#21 2022-10-17 14:21:58

Re: [SOLVED] Weird artefacts on one of my screens

#22 2022-10-18 16:33:59

Re: [SOLVED] Weird artefacts on one of my screens

#23 2022-10-18 19:36:33

Re: [SOLVED] Weird artefacts on one of my screens

#24 2022-10-19 05:23:29

Re: [SOLVED] Weird artefacts on one of my screens

#25 2022-10-19 06:04:09

Re: [SOLVED] Weird artefacts on one of my screens

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