Here are recommendations from OBS website
CPU Advice
- Set FPS to 30
Game Advice
- Try to aim for the highest bitrate possible for high motion games
- Use game capture if possible for maximum performance.
- Use window capture with Aero enabled if game capture is unavailable.
Network Advice
- Your upload speed is sufficient for 480p / 720p
- Considering lowering your buffer size and/or bitrate if you experience in-game latency
- Enable CFR for compatibility with streaming services
- Enable CBR for improved stream stability
- Recommended max bitrate: 935
- Recommended buffer size: 561
And, I recommend to check out this website/forum also.
https://v1.xspli*****m/forum/viewtopic.php?p=55228