CTD after about 10 seconds in-game

[Bac0nati0n]

In that case try removing NMC as said the game is not great when it comes to VRAM usage, I had a 5870 and the game did crash at regular intervals, I didn't think much of it because I'm used to games that use Bethesdas "customised" Gamebryo engine crashing. I replaced it with a 3GB 7970 and now my game doesn't crash (NMC medium). In fact I've been able to push it quite far, for a screenshot I spaŵned nearly 200 NPCs, the frame rate was terrible but the point is it didn't crash. I've also set up 30 vs 30 fights through the console and they run perfectly without a single glitch. The latest thing I did again for a screenshot was to place a nuclear blast in the middle of 60ish spawned NPCs, again it didn't crash. Attempts to do similar things with the old 1GB 5870 never ended well. The game does appear to be very sensitive to VRAM as Luthienanarion says.

 

Edit: Also try this http://newvegas.nexusmods.com/mods/35262 you'll need the alternate version of NVSE with it http://nvse.silverlock.org/beta/fnv4gb_nvse.zip

 

The thing about NMC is that I was able to play a character with it enabled all the way up to new vegas with no problems at all... it only started affecting my game after i had updated my current mods and created a new character.