4k Monitor stuttering on video playback

[Ruo94]

Hey y'all

My 4k main monitor is experiencing a lot of video playback stuttering, when not playing videos on 4k. This is very noticeable on youtube, Twitch and sometime on Netflix.

This stuttering only occurs when the video is not on 4k, or when the video is not on full screen. It's not a problem on my other 2k monitor. (I don't use that monitor for medias coz the colours are not as good.) 

I don't know if it's something normal with dual monitor setup, but it's really annoying when watching videos at 1080p or 1440p.

I've tried changing the cables, re-installing my GPU drivers, to no avail. My entire system is ~7 years old, except for my GPU. 

Could it be the monitor that's bad? somekind of bottleneck in my system? 

 

Setup:

Monitor 1 (4K): LG 27UD88, DP

Monitor 2 (2K): AOC AG271QG, DP

 

GPU: RTX 3070

CPU: Ryzen 7 2700

RAM: 16GB GSkill tridentZ 3200mhz

 

Thanks in advance!

[e22big]

It doesn't look that bad, if there's no hardware issue then it could be from the browser, maybe switching between Edge and Chrome and see how thing goes?