Question Horizontal bar appearing for a second when booting PC or running full screen application

Ishit Arya

Feb 27, 2014
These horizontal bar appear when I enable Freesync ultimate in monitor OSD and Adaptive sync in Nvidia Control Panel or when there's a voltage fluctuation.

Case-1 (Adaptive Sync enabled)
I always get horizontal bar when I boot my PC or switch back and forth from desktop to a full screen application whenever Freesync Ultimate and Adaptive sync are running. These bar also appear when there's voltage fluctuation.

Case-2 (Adaptive Sync disabled)
When Freesync and adaptive sync are disabled I don't get horizontal bar when booting my PC or switching to fullscreen application but I get those horizontal bars when there's a voltage fluctuation. Voltage fluctuation happens rarely but when it does these horizontal bar always appear for half a second and sometimes I even hear thump sound coming from Monitor speakers for a second.

Horizontal bar appear when Freesync and adaptive sync are enabled and also when there's voltage fluctuation in Case-1 but in Case-2 these horizontal bar appear only when there's voltage fluctuation.

Image of Horizontal Bar

I want to know whether it's my GPU which is causing these bar to appear or is it my Monitor. When I was trying to recreate horizontal bars in order to take pictures of them, I had to switch from desktop to fullscreen application multiple times which later causes this strange GPU artifact to appear. This artifact appeared right when my entire monitor colour went red for a split second.

Image of GPU Artifact

My Specs-

Zotac RTX2080 (Model no. ZT-T20800G-10P)
Monitor- Samsung LC27F591FDWXXL
Display Port- Vesa Certified Club3D CAC-2068