I can’t believe, this is a secret. But since it is, I’ll disclose it for you!
The bottom line
Yeah, I’ll begin at the end. Deal with it!
GeForce Experience[www.geforce.com] is a tool to automatically scan your system, determine the best settings and, well, set them.
So, start GFE and take a look at the settings window.
The default settings are pretty much perfect, except for the folders. You really should follow my setup. Namely including only the Common and [YourSteamAccountName] folders. If your Steam is in the default folder, exclude it.
Download the game (duh!) and start it. Quit it right afterwards. Trust me, I’m an engineer!
Start GFE and right on the front page, you will find a “Scan” button. Use it.
As you can see, Fallout: New Vegas is not optimized. No problem, just click the “Optimize” button and viola, graphics settings tailored for YOUR rig. Without any effort on YOUR side!