I have noticed that Firefox consume a lot of CPU, heats up computer and drains battery. Attached picture shows usage in safe mode. Everything is up-to-date (fresh system is installed today). Also, all drivers are up-to-date. When watching youtube usage goes even higher. I have never experienced such a thing with Mozilla. Any advice? Same thing with 3D acceleration on/off. I'm running laptop dell 3147 Pentium N3530, 8Gb RAM and 480 ssd. My other computer is older and usage for firefox while watching youtube range from 3% to 15%.

ps. I apologize for any mistakes made in grammar but English is not my first language