Question Geforce gtx 950m not working efficiently.

[Lvugys]

hello, i'm worried about my GPU Geforce gtx 950m (2gb) actually my laptop says 4 gb, however it's using maximum 1 gb out of 2 and its very rare, average is 500 mb. so i watched some youtube videos where people were people were playing gta 5 with 60+ fps normal graphics and i can't even play gta 4 without lags. i might buy new laptop or even pc sometime because it's 10 years old but what should i do now to increase efficient of my gpu? just to know other specs are: core i7, 16gb ram ddr3 2 modules, windows 10, drivers are updated.