Question New 2nd monitor, noticing visible lag in csgo UNLESS I have a fullscreen youtube playing on 2nd monitor

[d0zerPC]

So this is very confusing. I first noticed this playing Valorant, it is visual lag almost like I am getting low FPS or playing on 60hz. I have a 165hz monitor, and get 300FPS in Valorant and CSGO. So when I noticed this lag in Valorant I started closing programs on my PC, when I closed Steam the lag stopped. But now when I play CSGO the lag happens as well, I tried several things, such as disabling CSGO's new anticheat, disabling the steam overlay, closing Valorant AC Vanguard. I noticed today that the visual lag stops if I have a youtube video playing in fullscreen mode on my 2nd monitor. My 2nd monitor is relatively new as of this week.

Main Monitor: ASUS ROG Swift PG278QR (Connected via DisplayPort) (2K Res, 165Hz)
2nd Monitor: ASUS VP28UQG (Connected via HDMI) (4K Res, 60Hz)
Video Card: MSI 2080 Super

If anyone has any idea why this is I'd appreciate some help, thank you!

Oh and it doesn't matter if the youtube video is playing on the 2nd monitor, it solves the lag if it's just paused and in full screen mode.

 

[Ralston18]

Use Task Manager/Processes tab to troubleshoot the problem.

Click the column headers to sort the data in descending order. May or may not be helpful but that is an available option. Check other tabs if and as necessary to view the "bigger picture".

Observe system performance first while playing Valorant and getting visual lag.

Then start the YouTube video but continue to watch what (if anything) happens/changes in Task Manager.

Especially so once the lag disappears.

 

[atomicETC]

Do you play CS in windowed or borderless window mode? If so, try changing it to fullscreen mode.

I have a similar problem, but fullscreen youtube video on 2nd monitor does not "solve" it for me.

Here, CS lags when I'm playing in windowed/borderless mode AND there's any video (twitch, OBS, youtube, VLC or any other player) on my second monitor. If the videos are minimized or paused the lag stops. The most weird thing is that fps remains high (~300). The only thing that worked for me is playing in fullscreen mode.

 

[d0zerPC]

Do you play CS in windowed or borderless window mode? If so, try changing it to fullscreen mode.

I have a similar problem, but fullscreen youtube video on 2nd monitor does not "solve" it for me.

Here, CS lags when I'm playing in windowed/borderless mode AND there's any video (twitch, OBS, youtube, VLC or any other player) on my second monitor. If the videos are minimized or paused the lag stops. The most weird thing is that fps remains high (~300). The only thing that worked for me is playing in fullscreen mode.

I play in fuillscreen mode. The FPS would remain high for me as well, it was just visual lag, choppiness. But FPS was fine.

HOWEVER, I am happy to report that this problem has stopped as of tonight. Not sure if steam or csgo had an update, but it isn't happening any more in csgo or valorant