pathfinder grid for 2d sandbox game

Hello, i'm creating a survival sandbox 2D game and I need a way to make a pathfinding grid through all the map or something like a "moving grid", that follows the camera (so that nearby npcs can move around). I'm using the A*pathfinder and when i generate a 100x100 nodes grid the fps falls dramatically, so i'm guessing i should go for the second option. Do anyone have any clue about how to make it work?

 

How often are you calling the pathfinding algorithm? Is it possible to reduce the number of calls you are making?

 

I will test that. I thought the fps drop was because of the high number of nodes