SureAI

my rig.. phenom 2 940BE@3.6
4gb ddr2
radeon 4870
windows 7 x64

I enabled all the performance enhancing settings in the nehrim launcher

i installed these mods.
Low Poly Trees http://www.tesnexus.com/downloads/file.php?id=33414 *made the most impact possibly due to overly complex meshes*
Low Poly Grass http://www.tesnexus.com/downloads/file.php?id=5434
Oblivion Stutter Remover http://www.tesnexus.com/downloads/file.php?id=23208 *be sure to read about settings for the .ini on the description page*

may help you guys may not.. but Nehrim is much more playable and enjoyable for me now..

good luck