Hi, I'm wondering if anyone ever had this issue or knows how to fix it. When I start my game, the fps is around 90-100. As I play it gradually decreases until eventually it's 10-20. I don't even have to do anything, just load a save and leave my character standing, and in a few minutes fps drops to unplayable levels.

My laptop is capable of running most modern games maxed out, so I assume it has to be game related. If anyone knows a solution to this problem, I would be very grateful.

Hmm, Fallout3's engine isn't known to be completely optimal with memory management, but it shouldn't run out of RAM can quickly.

Do you have a lot of mods? Try to minimize the how amount of applications in-memory before loading Fallout 3.

Can you post a dxdiag report, please?

You mentioned you are playing on a laptop. Make sure it is not overheating.