When I bought my ATI 7970 around march of this year, I thought now that I have 3gb VRam i can install all sorts of graphics mods without any problem, mainly because that is what I read everyone sayin i.e. "you can never max out so much vram". Now after installing loads of graphics mods with ENB & Climates of tamriel my game is freezing/CTDing after every few minutes.
I guess you can never have enough VRam especially if you plan to heavily Mod Skyrim.
My system:
Intel core i7 2600
Corsair 8GB DDR3 RAM
ATI HD7970
Windows 7 Ultimate 64
Catalyst 12.8 drivers