postal001

Try running LOOT to sort your game. Works for my game.

Can you explain what happens to the gpu when the card attempts to access more than 2gb of vram?

...the card will still use 4gb of vram.

Have you played the Baldur's gate series?

I would start by disabling all the texture mods first, to see if that gets rid of the stutters.

Why is it a waste? Skyrim will use all 4gb of vram with enough textures.

What resolution? Which setting (mid, high, ultra)?

Read: Skyrim Project Stability http://www.nexusmods.com/skyrim/mods/32363/?

Skyrim Project Stability http://www.nexusmods.com/skyrim/mods/32363/?

Are you using ENBoost?

Yes.

At what resolution? What fps do you expect?

What have you done to try and resolve this?

How to ask for help: http://forums.nexusmods.com/index.php?/forum/414-skyrim-technical-support/

Does this happen with a new game?

Are you level 10 or higher? I think Dragonborn starts when your character's level 10.

Just for reference: Using a single r9 290x I get around 30 fps in Riverwood at 1080p using tons of visual enhancement mods and full version of realvision.

Personally, I like having lots of mobs to kill and to be killed by, so I like ASIS, OBIS, Immersive Patrols, immersive creatures and high level enemies.

Yes, but you don't get double the vram using two cards.

You could try Imaginator and Dynavision to improve the look of your game with minimal fps loss.

Try ENBoost and Safety Load if you're not using them.They can help reduce cdts.

Use Mod Organizer. You'll never have to reinstall Skyrim again.

What's your GPU specs?

Are you using Safety Load? http://www.nexusmods.com/skyrim/mods/46465/?

Use Mod Organizer to download and install mods. It'll keep you sane. http://www.nexusmods.com/skyrim/mods/1334/? I would start out slowly and add a few texture mods to get the hang of using Mod Organizer.