Greetings! I've been playing Skyrim for 3 months and I just realized the game is utilizing only 1 out of 2 GPU cores (NVIDIA GeForce GTX 690). This is despite the fact that I forced the game to use both cores through the NVIDIA control panel. I feel a little embarrassed that I came to this realization after playing for so many hours, but apparently Skyrim does not support dual core GPUs? I feel like I'm driving a Lamborghini with only half the cylinders working. I have been experiencing an annoying amount of stuttering lately (I use a lot of texture mods) even though I have vsync enabled.

http://itcprosolutions.com/skyrimguides/tweak_guide.htm

http://www.geforce.com/whats-new/guides/five-fast-elder-scrolls-v-skyrim-tweaks-guaranteed-to-make-your-game-look-even-better#1

http://www.geforce.com/whats-new/guides/the-elder-scrolls-v-skyrim-tweak-guide#1

The Nvidia Geforce GTX 690 only has 2GB per GPU core (standard configuration: 4GB total), so the texture mods may be maxing out available VRAM. Basically you only have 2GB of VRAM, which may not be enough for your mods.