Lag in OBS
Lag in OBS
I understand the issue isn't with your setup but how it appears on your screen. The OBS window might be rendering differently depending on the display settings, and lowering the bit rate could help if the original resolution is too high for your monitor. Check your monitor’s native resolution and adjust accordingly. Your specs look solid—consider testing at a lower resolution to see if that improves the experience.
I understand your system is running slow—upgrading this summer will help. To disable the preview, follow the steps in your app settings or preferences.
Which game are you asking about? What resolution do you need?