As seen on https://www.reddit.com/r/firefox/comments/guapaj/odd_flickering_with_hardware_acceleration_on/

The original problem only seemed to occur when watching a video and browsing within any other tab, no issues would occur until a video (which I assumed was using HWA) would be opened, and then this flickering would occur

It was played by Firefox, the video was a Twitch stream, on a second monitor

Disabling WebRender works around the issue.

Do the newer 451.xx series help with this? Is HW-Accelerated GPU Scheduling enabled?

This repros without hardware scheduling enabled. I'm a dev on the Windows DirectX team and have been seeing this on the latest public Windows 2004 release (not sure if it reproed on 1903). This looks a lot like WebRender may not be correctly synchronizing across D3D contexts before presenting to the DirectComposition swap-chain or virtual surface. Does WebRender use a swap-chain or a virtual surface image source? Alternatively there could be a bug in the Windows side regarding synchronization of virtual surface image sources, but if you're using a swap-chain then it's almost certainly a WebRender synchronization issue. It appears to repro more reliably on many-core CPUs such as Threadrippers.

Assuming it's not wonky interaction between D3D and FF, has this gone away since FF80 or with NVidia 452.06 drivers?

Still flickering. Nvidia driver 457.30 (But have seen this on all driver versions since updating to Windows 2004). Windows 19042.630. Dual screen setup 2*WQHD. One 144Hz the other 60Hz. Always reproducable:

1. Run Video (VLC, Potplayer, but actual software doesn't seem to matter)
2. Scroll a webpage in Firefox like www.spiegel.de . Or just go to this one here https://whois.domaintools.com/ and moved the mouse across the page

Tried a clean profile in Firefox with default settings no change still flickering.

When going back to 120Hz or less on the high refresh rate display there is no flickering. On the other hand Firefox is the only software showing this odd behaviour.

Zachary, Firefox is using a VirtualSurface image source for scrolling. Do you have any suggestions for how to debug this?

Just to give an update from my side.
-flickering only happens on the 144Hz Display when set to 144Hz, the second display never shows flicker
-flickering only happens in Firefox
-switching the refresh rate to 120Hz without restarting Firefox makes the flickering go away - reappearing when going to 144Hz again
-GSync on/off - no difference
-Nvidia Low Latency mode settings - no difference
-condition to trigger the flickering seems graphic activity on both displays at the same time (not only when playing video) - moving the mouse around on 60Hz display can trigger the flickering
-https://whois.domaintools.com/ with an animation flickers massively when preconditions are met - no scrolling needed

I just saw that Geforce 457.51 were released today. Nothing in release notes jumped out at me as it relates to this bug but wanted to mention one thing I saw in them in case it might be related.

• When setting the refresh rate higher than 100Hz, the color format switches from RGB to ycbcr422. [3053990]

Thank you. But I don't think this is related, at least on my computer. The two WQHD displays I use only support RGB 8bpc and they are connected via Displayport. Refresh rate on the 144Hz display is also confirmed in the on screen menu of the monitor. So the refresh rates set in Windows seem to be correct.

Can confirm I have the same issue as Gerd B.

Two displays. one 1080p 60Hz, one 1440p 144Hz. Issue manifests ONLY when in 'duplicate these displays' and in 144Hz. Switching to 120Hz in the Nvidia drivers (Windows settings don't give me this option when duplicating displays) fixes it.

Started happening immediately after I upgraded from Windows 1903 to 21H1. Updating to latest nVidia driver didn't help.

The flicker shows parts of a video playing on a second monitor. I second what others are saying here: my setup is a 165 Hz monitor (where the flicker shows) and a 60 Hz monitor (where the video plays).

Can we upgrade severity to S2? There is no satisfactory work-around.

It seems dup of bug 1638709. The problem might be addressed by pref gfx.webrender.compositor=false at about:config.

Roman, which version of Firefox do you use? If the problem is dup of bug 1638709, native compositor is disabled on beta and release by Bug 1704954.

I'm on 88.0.1, pending a restart. "about:support" shows Compositing: WebRender. Sounds like you're on top of this already. Looking forward to go back to the webrender compositor at some point!

same problem here with dual monitor one is 280Hz the other is 60Hz
and it occur only on my 280Hz monitor
I need to turn the 60Hz off if I wanted to stop the flickering

Any improvement here with Win 10 21H2 and NVidia 497.09?

Bug still present in my configuration:

Windows 10 Pro x64 Version 21H2
NVIDIA Driver Version 456.71
Firefox 102.0
Thunderbird 102.0

This bug affects both Firefox and Thunderbird.

(In reply to fell from comment #18)

Bug still present in my configuration:

Windows 10 Pro x64 Version 21H2
NVIDIA Driver Version 456.71
Firefox 102.0
Thunderbird 102.0

This bug affects both Firefox and Thunderbird.

A driver update to 516.59 seens to have stopped the flickering, but there is still noticable stuttering when scrolling compared to single monitor operation.

Redirect a needinfo that is pending on an inactive user to the triage owner.
:gw, since the bug has recent activity, could you have a look please?

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