Fallout 4 bad fps

So the problem i am having is that my fps is good at times when i'm just outside in the commonwealth. But once inside it sometimes drops to 30-40 fps or lower. On the outside it sometimes dops to 45 aswell (in my base). I am playing on low settings wich my laptop should totally be able to handle!

My build is:

> Motherboard : Micro-Star International Co., Ltd. MS-1763

> Chipset : Intel Haswell

> Processor : Intel Core i7 4800MQ @ 2700 MHz (max : 3885)

> Ram : 8192 MB DDR3-SDRAM

> Graphics card : Gefore GTX 870m

> Windows 8.1 Home Edition 6.02.9200 (64-bit)

> DirectX : Version 11.00