I used to play Fallout 3 on console when it first came out and absolutely loved it, so when I switched to PC, I decided I'd buy it again to get a smoother/more immersive experience. Unfortunately, I've had a very strange problem with the game's speed. No matter how I change my graphical settings, everything seems to move quickly in some areas (Such as megaton) and at normal speed at others (Mostly out in the wasteland and open areas). I've spent hours trying to find a solution to the problem, and I've seen a few ways to "fix" the problem by editing the .ini file. No matter what I try, it has the same speed problem. I don't really have any more options at this point.

I've heard it might be because my dual core processor is running too fast for the game to handle, but I'm not sure if that's true or not. If so, how would I force the game to only use one core?

Ive done this before with a game.

Im not sure whether this will help, look for the game icon and go into properties?
there might be a setting in there. not too sure was a while back

The problem is most likely that you don't have an fps cap. The only solutions without mods are turning on vertical sync and the fpsclamp setting, both of which can cause issues. If you don't mind mods, you can download http://www.fallout3nexus.com/downloads/file.php?id=8886 mod to set an fps cap. I had the same problem and it worked great for me. I set the fps cap to about 40-50 and the timing feels good. Make sure you also download http://www.fallout3nexus.com/downloads/file.php?id=8606 which is required for the above mod.

Thanks, I'll try that out.

It worked!

Thank you very much, the game runs perfectly now.