fps
Your FPS is gradually decreasing after 30 minutes of play, dropping from steady 60 to unstable 45. It’s unclear what’s causing this issue... Your laptop: http://www.mygadgetsmall.com/shopping/hp...d_367.html
Use MSI Afterburner to monitor CPU and GPU temperatures; if they rise excessively, it may indicate overheating.
That’s a good start. Let’s consider heat as our initial hypothesis.