(PG34WCDM) White horizontal lines on ultrawide OLED with VRR

[PWN3D_]

Update;

I have an answer from Asus support. They manage to reproduce this behaviour on their side with a 4060, but they first seems to put this kind of artefact on the panel and the OLED technology and argued that this is happening also on other monitors brand.

I just tested the LG 34GS95QE and send them the new footage, and I couldn't reproduce those withe lines anymore. Same PC, same DisplayPort Cable, same port.

LG 34GS95QE

phpBB [video]

PG34WCDM

phpBB [video]

They now seem to acknowledge the situation after these new video capture and are now "working on it".

I am uncertain whether this issue is due to a manufacturing or if it can be resolved with a software update, but it certainly concerning.

[PWN3D_]

Just letting you all know that Asus release a new firmware (MCM106) for this monitor that is getting rid of those lines so far after a few minutes of test on SmoothFrog.

It seems like it was just a firmware bug on their part, a bit too long from them to realize that, but at least they finally worked on it!

Edit: Unfortunately, the new firmware did not completely resolve the issue. There is some improvement, as the problem is not as easily reproducible as before in SmoothFrog.I am still in contact with ASUS support, providing them with additional video captures and awaiting their feedback.

Edit 2: Probably final update on this issue : Few days ago, Asus privately shared a beta firmware that I've tested and it seems to get rid of those lines so far. I could not reproduce them even on situation where I 100% could before. So I guess the next official firmware (MCM107) while hopefully get rid of those artefacts. Glad that the engineers finally figure it out.

[alawamiaz]

This issue seems also to happen on my Lenovo Legion Pro 34WD-10 which i bellieve uses same panel. Only happens with aggressive frametime instability in the lower VRR range. I can't seem to get in contact with lenovo actual techincal support aside from dumb generic tech replys from their email.

Have you coampred EDID before and after firmware update? i suspect the issue is related to vblank/porch sizes.

[Aeon]

same issue with 480hz WOLED LG 27GX790A-B on the latest firmware
seems like only WOLED issue, haven't seen reports with QD-OLEDs

it mostly happens at the top part of the screen (in the back porch presumably?).
any idea what I can try to change in CRU? higher/lower back porch + blanking?

tried different refrsh rates (240hz) and minimum VRR range (48->120hz) didn't help unfortunately