I fixed my stutter problems on 3 months of gameplay for set itexmipmapskip=0 to itexmipmapskip=1! O.o

I read on itexmipmapskip option is recommended for 512mb videocards and I have an ATI HD5850 1gb DDR5 OC to 880/1170. Why my stutter problems was always this option disable if my card have 1gb VRAM? I don't have process injectors only Realistic lightning mod and HD textures DLC with STEP recommended textures (1024 versions on SkyrimHD 2k, realistic smoke and embers and deadlyspellimpacts). My textures are DDSopted and I have HQLODs mod by Ethathron.

What is itexmipmapminimum?

It seems to reduce texture quality, which makes sense since it's mipmap related.