Asus laptop lag issue

Henry_63

Commendable
Dec 7, 2016
7
0
1,510
My newly purchased Asus gaming laptop. I use Firefox, for a while i can watch youtube video at 1080p360 smoothly then soon after the video starts lagging and everything else in other tabs lags skips when i scroll down and up badly, I expected lag free performace at all times. Is normal? What could be causing it?