I had the same problems with Fallout 3 on an older machine: Some Intel board (Can't remember the model), Quadcore CPU with 2.4 GHz, NVidia 8800 GTX, Windows XP 32 bit. My system: Asus P7P55D Pro, Intel Core i7 2.8 GHz, 4 GB RAM, NVidia 285 GTX, Windows 7 64 bit. Are there more known configuration settings I could try out to get a smooth and fast game play? So with these two settings, no option is acceptable. Disable vsync and disable iFPSClamp: Screen-Tearing.

Disable vsync and enable iFPSClamp: Screen-Tearing and game play is too fast (When FPS is the double of the iFPSClamp value then game play is twice as fast).Enable vsync without iFPSClamp: No screen-tearing but game stutters even when FPS is high.Enable vsync and iFPSClamp: No screen-tearing and smooth game play but slow-motion in some areas.Some regions in the game are producing significant FPS drops which seem to be unrelated to the video settings. Another problem is that this also happens on the lowest video settings. But as soon as it drops to a FPS like 50 the game runs in slow motion, which is also not acceptable. There are fixes however, and this guide will help you in getting the most out of your Fallout game. Since you're here, that probably means that you are the victim of one or more of these afflictions. With this setting the game is absolutely smooth as long as the FPS does not drop below 60. While Fallout: New Vegas is an excellent game it is also right with bugs, glitches, and performance issues. The only solution I found so far is setting the following option in fallout.ini: iFPSClamp=60 This is especially noticeable when moving sideways. Afterwards, the FPS stabilized at 60, but the game stutters. But I hate playing without vsync because the video tearing is unbearable, so I enabled it. The game normally runs with 70-90 FPS on highest settings when not using vsync. I'm playing Fallout: New Vegas on a decent machine.

Fallout new vegas lag fix