My laptop can run New Vegas with mods, so I'm having trouble seeing how this can run slower on the same machine. The real-time rendering of 'static images' doesn't add anything besides processor load.
New Vegas is hardly a game that taxes graphical processing, even when it came out.
Its biggest performance issues, just like Fallout 3, is the bloody Gamebryo engine being a piece of crap.
Are you running texture mods?
Performance/stability enhancing mods?
SweetFX/ENB mods?
Are you staying away from mods that boost graphical quality, and only using mods that don't increase visual fidelity/quality?
Companion mods?
Unofficial bugfix mods?
NVSE? (This one should be a no brainer for most mods, and the game itself if you've got more than 4GB RAM.)
Like Doc Kimble already said, unless you're posting specs, saying that the game doesn't run well for you, while a significantly older game apparently performs better, despite you giving no indication of how well said older game is actually performing.