Question / Help Game FPS drop with 2nd monitor

[hawk]

LOG: https://gist.github.com/anonymous/278f422bd823dab7d1b8

I can stream fine with no lag or anything, but when I put the OBS window over on my 2nd monitor, the game lags and stutters every 5 seconds. If I move the window back to the primary screen, the lag is gone, the stream is still going.
I get the same thing when I have youtube playing on the 2nd monitor and streaming. It feels like the youtube video or OBS screen is getting priority over my game, like if you ever play a game in window mode and then click outside the game, the game then drops FPS.

Games I play are Diablo 3 and CS:GO (Full screen). Both games give the same problem when showing OBS on my 2nd monitor. I can get by with it being on the primary monitor, but I would like to see if I drop frames or if I switch to the wrong scene. I think the OBS log covers the rest of the information.

 

[Jack0r]

The timings from OBS in that log look very good. A few duplicate and late frames but nothing to worry about. You could try deactivating the preview in OBS, see if that has a positive effect.

In general its known that multiple monitors can have an effect on the performance, they even increase the energy consumption of your system, but I normally have no big problem putting OBS on the second display. (flash can be a bigger problem, its just bad)

 

[hawk]

Disabling the view screen works as well. When OBS is viewing, the CPU and GPU usage drop from above 50%, below 10%. It's like the computer is focusing resources to OBS and everything else is getting background priority.
If OBS isn't streaming or previewing, I can watch 1080p videos on the 2nd monitor with my ingame problems. Once OBS gets involved, CPU & GPU usage globally drops under 15% at least.

 

[D2ultima]

There is an issue in windows where content on the second screen messes with content on the first screen as said above. It depends on the game and the demand of the video being rendered, and is slightly mitigated by forcing Windows Timer Resolution to 1ms instead of the default 15.6ms in Windows 8. I do not know if the same fix works for 7, however as you discovered, disabling the video preview in OBS works.