Issue: OBS running (even when not streaming or recording) is causing noticeable lag and stuttering while gaming.
That is a common observation by new users to OBS Studio, including observations about drop in game FPS, etc...
Such system behavior is normal/expected/by design... you are asking your PC to do a LOT of work, and the impact is noticeable...
The computationally demanding work is the upfront rendering/compositing/etc .... all of which happens when OBS Studio is running and you have any Scene with an active video source (ie, creating the Preview Scene; 2X workload if running in Studio Mode)... if numerous CPU impactful Audio filters/effects, that can also be an issue (though usually less resource demanding than processing video).
- And yes, that does mean that if you don't need Studio Mode (I don't), not using it can usually reduce system workload (hardware resource utilization)
Outputting that composited result (to Record and/or Stream), depending on settings, is not as system resource impactful, relatively speaking. sorry, it depends. And others would know far more than I on the nuances...
Running a computationally demanding workload (like OBS Studio) requires resource management. Also, some settings often recommended for 'peak' gaming experience, conflict with getting a smooth/clean compositing/livestream. For example, running multiple monitors at different refresh rates is somethign Windows OS has been known to struggle with at times. And then there is having uneven refresh rates vs FPS. Having FPS and refresh rates being an even multiple of each other often helps (ex 120MHz refresh rate with 60fps capture). Not recommended is 144MHz refresh and 60 fps.
Also, you are on a laptop, which can thermally throttle much easier, so up to you to figure out how to monitor for such and then determine is performance ok for you when throttled, or if you need to adjust to ensure system doesn't throttle (or at least as much).
The settings adjustments mentioned above are places to start. Whether you need to do more 'optimizations' at Operating System level or in OBS Studio ... depends on your specific system setup (exactly what is running in background), specific games, your expectations, etc.
