Fallout: NV stutters even though FPS is high

I'm playing Fallout: New Vegas on a decent machine. The game normally runs with 70-90 FPS on highest settings when not using vsync. But I hate playing without vsync because the video tearing is unbearable, so I enabled it. Afterwards, the FPS stabilized at 60, but the game stutters. This is especially noticeable when moving sideways. The only solution I found so far is setting the following option in fallout.ini:

iFPSClamp=60

With this setting the game is absolutely smooth as long as the FPS does not drop below 60. But as soon as it drops to a FPS like 50 the game runs in slow motion, which is also not acceptable. Another problem is that this also happens on the lowest video settings. Some regions in the game are producing significant FPS drops which seem to be unrelated to the video settings.

So these are my current options:

• Enable vsync and iFPSClamp: No screen-tearing and smooth game play but slow-motion in some areas.
• Enable vsync without iFPSClamp: No screen-tearing but game stutters even when FPS is high.
• 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).
• Disable vsync and disable iFPSClamp: Screen-Tearing.

So with these two settings, no option is acceptable. Are there more known configuration settings I could try out to get a smooth and fast game play?

My system: Asus P7P55D Pro, Intel Core i7 2.8 GHz, 4 GB RAM, NVidia 285 GTX, Windows 7 64 bit.

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.

The problem isn't video-related; it's your hard drive subsystem. Your computer is bogging down (like mine) when it's loading new terrain as you walk. In a "sandbox" game like this, the computer is always downloading new "mini" maps as you move over the landscape. (Look at the "local" map on your PipBoy while outside, you'll see that it's a small fraction of what you can see. As you cross the borders of these small maps, the game has to load the new map from the drive.) I have 2 10K Raptors (from many years ago), STRIPED, and I still get very noticeable lag when this happens. I would really like to upgrade to an SSD(s). The latest figures I've seen show that a single, mainstream SSD would be 30 TIMES FASTER than my stripe set. :-(