If you have an nvidia card, especially a 4xx fermi card do NOT use the new 260.89 drivers for this game. Go read the nvidia forums, this drive svcks for older game engines and NV has an older game engine and is affected by this driver. Go to nvidia's website and download 260.63 from beta/archived drivers. The 260 series is mainly for performance improvements on 4xx fermi card (desktop and mobile) so owners of 3xx, 2xx, 1xx, 9xxx, 8xxx, etc should try drivers from 25x or older series - pertaining to new vegas specifically. If using the current WHQL 260.89 drivers, you will see a FPS improvement by turning down the water multisampling quality assuming you can get it to work and save. Steam saves a few copies of falloutprefs.ini so it is entirely possible than nothing you change there will take effect. Try this out:

In the launcher, select the highest settings you think your video card is capable of (ex - gtx 460 should choose ultra). Next turn anti aliasing off in the launcher (I know, but just do it anyways). Leave anisotropic filtering at 16x. In advanced, uncheck transparenecy multisampling. If these settings do not save, make sure that in the numbered cache/temp folder in program files(x86 if on 64-bit os)\steam\userdata\random number\today's date or installation date folder\falloutprefs.ini and your mydocuments\games\falloutnv\falloutprefs.ini are identical. Change imultisample=0 and btransparencymultisampling=0

If you can force AA and transparency multisampling (supersampling will reduce performance) in the nvidia control panel, do it and set AA to override at least to 4x. Thing is, I've tried three drivers and cleaned each and these settings have no affect on gameplay. Some users here claim it does, but I wouldn't put it past them if they just don't notice there is no AA at all either (no offense, but some people thing 24fps is smooth here)

That's my story. Turn off in-game AA and don't use Monday's driver update. It increases FPS around NPCs that talk or factions that shoot at you and also it reduces stuttering. Plus it completely eliminates those random white blobs

Mines been off from the start and I still get the "look at an NPC and you ded" lagfest.

I can't find the drivers.

Uhm, are you sure about the drivers? Wouldn't that negatively impact just about everything else? Also, direct links, please?

Here's something to try--in the Nvidia control panel, set Maximum Pre-rendered Frames to 1 instead of the default 3. I've found that it has improved my framerate.

I'm using the new 260.89 drivers and a GTX460.

I'm definitely sure. Nvidia control panel has no effect. I see jaggies and I bet other users are just [censored] seriously (seriously, they turn in-game AA off and control panel AA on which doesn't work and can't tell a difference cause they were born with an extra chromosome or something)

http://www.nvidia.com/object/notebook-win7-winvista-260.63-beta-driver.html

Use this, turn AA off

Alright, downloading now. Thanks, man. I hope this doesn't decrease my performance in other games, though.

Will I need to clean up my other drivers with DriverSweeper?

Same for me stil even with that driver. I have a 9800m GS

He said the drivers are mainly for the 4XX series.

Umm, the drivers are for 32bit and I run 64bit. And Whenever I tried to download the 64bit version, it said the drivers weren't found.

:/