Weird Display Artifacts when Freesync is Enabled

[sam_86314]

I recently decided to replace my current monitor (Monoprice 35" 3440x1440 100Hz, bought in 2020) due to some issues I've had with it. The replacement is on the way, but in the meantime, I want to figure out what this one particular issue is.

Whenever Freesync is enabled, I randomly get this weird gray pattern on screen. It shows for maybe one frame, and then it's gone. I'd describe it as like a net or woven pattern almost.

Today, I decided to film the screen with my phone while running the NVIDIA G-Sync Pendulum demo, and I was able to capture it.

Click on the image to expand it.

So it's like the image gets divided into squares where every other pixel does weird things.

It seems to mainly happen when the refresh rate dips below 48Hz and LFC kicks in, and even then, it only happens occasionally. But when it does happen, it's extremely jarring and annoying enough that I don't use Freesync.

I've tried adjusting monitor settings, using a different DP cable, and even adjusting the point that LFC kicks in, and it still happens.

Anyone experienced something similar or know what exactly is causing this?

 

[Bill_Bright]

Did you try a different monitor on that computer, or that monitor on a different computer just to make sure it is the monitor and not the computer?

 

[sam_86314]

Did you try a different monitor on that computer, or that monitor on a different computer just to make sure it is the monitor and not the computer?

Just tried it on two different PCs (Vega 448SP and GTX 1070) with Freesync/G-Sync enabled on both (verified that the refresh rate is changing and LFC is working in the monitor's OSD).

So far, I'm not getting the artifacts. The worst I'm getting is a slight gamma shift when LFC happens, which is normal from what I've heard.

So, it might be a problem with my 6800 XT. That really sucks. I guess I'll try the other DisplayPorts and maybe the other BIOS to see if that affects anything.

 

[AusWolf]

It sounds to me like your monitor handles LFC particularly badly, or is faulty.

As far as I know, LFC works differently with Nvidia, so only getting issues with AMD is a possibility, but that doesn't necessarily mean that it's the GPU's fault.

 

[sam_86314]

Switching to a different DisplayPort didn't help. Setting the Pendulum demo to cycle between 49 and 51FPS seems to be the way to get it to happen consistently.

I had been messing with CRU to try and fix the high VRAM clock issue, so I've completely reset CRU to see if those settings were causing issues.

It's annoying because it'll seem fine for a while, and then the issue will suddenly crop up.

EDIT: Been running the demo for a few minutes now (cycling between 45 and 55 FPS) after resetting CRU, and so far it's been fine. Still need to try games, but I guess that might've been the issue.

 

[AusWolf]

Switching to a different DisplayPort didn't help. Setting the Pendulum demo to cycle between 49 and 51FPS seems to be the way to get it to happen consistently.

That's the range that triggers LFC to switch on and off at a rapid rate - that's where LFC-related monitor issues come out.

I do think that something is wrong with your monitor. Backlight/gamma flicker is unfortunately normal, especially with a VA panel, but a chequered pattern, not so much.

 

[sam_86314]

Yeah, after resetting CRU, it seems to be fine.

I also ordered a certified DP 1.4 cable yesterday, and it's arrived so I've switched to it.

I had the timing set to CVT-RB because that seemed to fix the high VRAM clock issue that all AMD cards seem to have. I guess Freesync doesn't play nicely with it.

Guess I'll just have to deal with higher idle power draw and temps.

 

[AusWolf]

Guess I'll just have to deal with higher idle power draw and temps.

That's unfortunately normal with an AMD card and high refresh/resolution displays. I'm glad you sorted the artefacts out.